Gourt Home::Gourt :: Conversion of units
This article lists conversion factors between a number of units of measurement.
Conversion techniques
The simplest way to convert from one unit to another is to carry through the units themselves in the mathematical operation. To illustrate this process, consider the following examples.
You would like to convert 6 feet into metres. Consulting the table below and finding that one foot is exactly 0.3048 metre, you can now perform the mathematical conversion:
- 6 ft × 0.3048 m/ft = 1.8288 m
Say your height is 183 centimetres, and you wish to convert this into inches:
- 183 cm / (2.54 cm/in) = 72.0 in
To check our answer, we convert this result back into feet:
- 72 in / (12 in/ft) = 6.0 feet
Multiple units can be manipulated in the same fashion:
- 7 mi/s × 1.609344 km/mi × 3600 s/h = 40,000 km/h
Thus, Earth escape velocity is about 7 miles per second, or 40,000 kilometres per hour. Notice that since the calculation started with one significant figure (the 7), the answer also has one significant figure (the 4 in 40,000).
Deciding whether to multiply or divide is determined by looking at the units and deciding which ones you want to "get rid" of. In the conversion just above, if we had divided by 3600 s/h instead of multiplying, the result would have come out in kilometre-hours per square second, clearly an incorrect and meaningless result.
See also
Rounding of results
An important thing to remember is that the process of making a conversion cannot give you any more precise results than what you started with. While many of the conversion factors given in the tables below are exact, and others while not exact contain many significant digits, all the numbers you get after performing calculations on a calculator or with pencil and paper are not meaningful.
After using these conversion factors, be sure to round off the results appropriately.
See also
Tables of conversion factors
| ≡ | definition |
|---|---|
| = | exactly equal to |
| ≈ | approximately equal to |
| (digits) | indicates the digits repeat infinitely |
Length
- | Name of unit | Symbol | Definition | Relation to SI units | - | metre (SI base unit) | m | ≡ m | = m | - | fermi | fm | ≡ 1.000 × 10−15 m | = 1.000 × 10−15 m | - | x unit; siegbahn | xu | ≈ 1.0021 × 10−13 m | - | Stigma; pm | ≡ 1.000 × 10−12 m | ≡ 1.000 × 10−12 m | - | Bohr radius | a0; b | ≡ α/(4πR∞) | ≈ 5.291 772 083 × 10−11 ± 19 × 10−20 m | - | atomic unit of length | au | ≡ a0 | ≈ 5.291 772 083 × 10−11 ± 19 × 10−20 m | - | ångström | Å | ≡ 1.000 × 10−10m = 0.1 nm | - | micron | µ, µm | ≡ 1.000 × 10−6m | - | twip | twp | ≡ 1/1440 in | ≈ 1.763 889 × 10−5 m | - | mil; thou | mil | ≡ 1.000 × 10−3 in | = 2.54 × 10−5 m | - | mickey | ≡ 1/200 in | = 1.27 × 10−4 m | - | point (ATA) | pt | ≡ 0.013837 in | = 0.351 459 8 mm | - | point (PostScript) | pt | ≡ 1/72 in | ≈ 0.352 778 mm | - | point (metric) | pt | ≡ 3/8 mm | = 0.375 mm | - | point (Didot; European) | pt | ≡ 0.376 065 mm | - | line | ln | ≡ 1/12 in | ≈ 2.116 667 mm | - | barley corn | ≡ 1/3 in | ≈ 8.466 667 mm | - | finger | ≡ 7/8 in | = 22.225 mm | - | inch | in | ≡ 1/36 yd | = 25.4 mm | - | calibre | cal | ≡ 1 in | = 25.4 mm | - | stick | ≡ 2 in | = 50.8 mm | - | nail (cloth) | ≡ 2 ¼ in | = 57.15 mm | - | palm | ≡ 3 in | = 76.2 mm | - | hand | ≡ 4 in | = 0.1016 m | - | finger (cloth) | ≡ 4 ½ in | = 0.1143 m | - | span | ≡ 6 in | = 0.1524 m | - | link (Gunter's; Surveyor's) | lnk | ≡ 1/100 ch | = 0.201 168 m | - | span (cloth) | ≡ 9 in | = 0.2286 m | - | quarter | ≡ ¼ yd | = 0.2286 m | - | link (Ramsden's; Engineer's) | lnk | ≡ 1 ft | = 0.3048 m | - | foot (Clarke's; Cape) | ft (Cla) | ≈ 0.304 797 265 4 m | - | foot (Sear's) | ft (Sear) | ≈ 0.304 799 47 m | - | foot (Indian) | ft Ind | ≈ 0.304 799 514 m | - | foot (Benoît) | ft (Ben) | ≈ 0.304 799 735 m | - | foot | ft | ≡ 12 in | = 0.3048 m | - | foot (American; U.S. Survey) | ft (US) | ≡ 1200/3937 m | ≈ 0.304 800 610 m | - | cubit | ≡ 18 in | = 0.4572 m | - | pace | ≡ 2.5 ft | = 0.762 m | - | yard | yd | ≡ 3 ft | = 0.9144 m | - | ell | ell | ≡ 45 in | = 1.143 m | - | fathom | fm | ≡ 6 ft | = 1.8288 m |
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| ≈ 1/1000 NM | = 1.852 m | - | rod; pole; perch | rd | ≡ 16 ½ ft | = 5.0292 m | - | rope | rope | ≡ 20 ft | = 6.096 m | - | chain (Gunter's; Surveyor's) | ch | ≡ 66 ft | = 20.1168 m | - | chain (Ramsden's; Engineer's) | ch | ≡ 100 ft | = 30.48 m | - | cable length (International) | ≡ 1/10 NM | = 185.2 m | - | cable length (Imperial) | ≡ 608 ft | = 185.3184 m | - | furlong | fur | ≡ 660 ft | = 201.168 m | - | cable length (U.S.) | ≡ 720 ft | = 219.456 m | - | mile | mi | ≡ 1760 yd = 5280 ft | = 1609.344 m | - | mile (U.S. Survey) | mi | ≡ 5280 ft (US) | = 5280 × 1200/3937 m ≈ 1609.347 219 m | - | nautical mile | NM; nm | ≡ 1852 m | - | nautical mile (Admiralty) | NM (Adm); nm (Adm) | ≡ 6080 ft | = 1853.184 m | - | geographical mile | mi | ≡ 6082 ft | = 1853.7936 m | - | telegraph mile | mi | ≡ 6087 ft | = 1855.3176 m | - | league | lea | ≡ 3 mi | = 4828.032 m | - | nautical league | NL; nl | ≡ 3 NM | = 5556 m | - | light-second | ≡ 2.997 924 58 × 108 m | - | light-minute | ≡ 60 light-seconds | = 1.798 754 748 × 1010 m | - | astronomical unit | AU | = 149 597 870.691 ± 0.030 km | - | spat | S | ≡ 1012 m | = 1 Tm | - | light-hour | ≡ 60 light-minutes | = 1.079 252 848 8 × 1012 m | - | light-day | ≡ 24 light-hours | = 2.590 206 837 12 × 1013 m | - | light-year | l.y. | ≡ c0 × 86 400 × 365.25 | = 9.460 730 472 580 8 × 1015 m | - | parsec | pc | ≈ 180 × 60 × 60/π AU | ≈ 206 264.806 25 AU= 3.085 677 581 3 × 1016 ± 6 × 106 m |
Area
| Name of unit | Symbol | Definition | Relation to SI units | - | square metre (SI unit) | m² | ≡ 1 m × 1 m | - | barn | b | ≡ 10−28 m² | - | circular mil; circular thou | circ mil | ≡ π/4 mil² | ≈ 5.067 075 × 10−10 m² | - | square mil; square thou | sq mil | ≡ 1 mil² | = 6.4516 × 10−10 m² | - | circular inch | circ in | ≡ π/4 in² | ≈ 5.067 075 × 10−4 m² | - | square inch | sq in | ≡ 1 in² | = 6.4516 × 10−4 m² | - | board | bd | ≡ 1 in × 1 ft | = 7.741 92 × 10−3 m² | - | square link | sq lnk | ≡ 1 lnk² | = 4.046 856 422 4 × 10−2 m² | - | square foot | sq ft | ≡ 1 ft² | = 9.290 304 × 10−2 m² | - | square yard | sq yd | ≡ 1 yd² | = 0.836 127 36 m² | - | cord | ≡ 192 bd | = 1.486 448 64 m² | - | boiler horsepower equivalent direct radiation | bhp EDR | ≡ (1 ft²) (1 bhp) / (240 BTUIT/h) | ≈ 12.958 174 m² | - | square rod/pole/perch | sq rd | ≡ 1 rd² | = 25.292 852 64 m² | - | are | a | ≡ 100 m² | - | square chain | sq ch | ≡ 1 ch² | = 404.685 642 24 m² | - | dunam | ≡ 1000 m² | - | rood | ro | ≡ ¼ ac | = 1011.714 105 6 m² | - | acre | ac | ≡ 10 sq ch = 4840 sq yd | = 4046.856 422 4 m² | - | hectare | ha | ≡ 10 000 m² | = 0.01 km² | - | yardland | ≡ 30 ac | = 1.214 056 926 72 × 105 m² | - | hide | ≡ 100 ac | = 4.046 856 422 4 × 105 m² | - | square kilometre | km² | ≡ 1 km² | = 106 m² | - | square mile; section | sq mi | ≡ 1 mi² | = 2.589 988 110 336 × 106 m² | - | square U.S. Survey mile | sq mi | ≡ 1 mi (US)² | ≈ 2.589 998 × 106 m² | - | township | ≡ 36 sq mi (US) | ≈ 9.323 994 × 107 m² | - | barony | ≡ 4000 ac | = 1.618 742 568 96 × 107 m² |
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Volume
| Name of unit | Symbol | Definition | Relation to SI units | - | cubic metre (SI unit) | m³ | ≡ 1 m × 1 m × 1 m | - | litre | L | ≡ 1 dm³ | - | lambda | λ | ≡ 1 mm³ | = 1 μL | - | drop (metric) | ≡ 1/20 mL | = 0.05 mL | - | minim (Imperial) | min | ≡ 1/480 fl oz (Imp) = 1/60 fl dr (Imp) | ≈ 0.059 193 880 208 333 mL | - | minim (U.S.) | min | ≡ 1/480 US fl oz = 1/60 US fl dr | = 0.061 611 519 921 875 mL | - | drop (U.S.) (alt) | gtt | ≡ 1/456 US fl oz | ≈ 0.064 854 231 mL | - | drop (Imperial) (alt) | gtt | ≡ 1/1824 gi (Imp) | ≈ 0.077 886 684 mL | - | drop (U.S.) | gtt | ≡ 1/360 US fl oz | = 0.082 148 693 229 1(6) mL | - | drop (medical) | ≡ 1/12 mL | = 0.08(3) mL | - | drop (Imperial) | gtt | ≡ 1/288 fl oz (Imp) | = 0.098 656 467 013 (8) mL | - | dash (U.S.) | ≡ 1/96 US fl oz = ½ US pinch | = 0.308 057 599 609 375 mL | - | dash (Imperial) | ≡ 1/384 gi (Imp) = ½ pinch (Imp) | = 0.369 961 751 302 08(3) mL | - | pinch (U.S.) | ≡ 1/48 US fl oz = 1/8 US tsp | = 0.616 115 199 218 75 mL | - | pinch (Imperial) | ≡ 1/192 gi (Imp) = 1/8 tsp (Imp) | = 0.739 923 502 604 1(6) mL | - | fluid scruple (Imperial) | fl s | ≡ 1/24 fl oz (Imp) | = 1.183 877 604 1(6) mL | - | fluid drachm (Imperial) | fl dr | ≡ 1/8 fl oz (Imp) | = 3.551 632 812 5 mL | - | fluid dram (U.S.); U.S. fluidram | fl dr | ≡ 1/8 US fl oz | = 3.696 691 195 312 5 mL | - | teaspoon (Canadian) | tsp | ≡ 1/6 fl oz (Imp) | ≈ 4.735 510 416 667 mL | - | teaspoon (U.S.) | tsp | ≡ 1/6 US fl oz | = 4.928 921 595 mL | - | teaspoon (metric) | ≡ 5 mL | - | teaspoon (Imperial) | tsp | ≡ 1/24 gi (Imp) | = 5.919 388 020 8(3) mL | - | dessertspoon (Imperial) | ≡ 1/12 gi (Imp) | = 11.838 776 041 (6) mL | - | tablespoon (Canadian) | tbsp | ≡ ½ fl oz (Imp) | = 14.206 531 25 mL | - | tablespoon (U.S.) | tbsp | ≡ ½ US fl oz | = 14.786 764 782 5 mL | - | tablespoon (metric) | ≡ 15 mL | - | cubic inch | cu in | ≡ 1 in³ | = 16.387 064 mL | - | tablespoon (Imperial) | tbsp | ≡ 5/8 fl oz (Imp) | = 17.758 164 062 5 mL | - | pony | ≡ 3/4 US fl oz | = 22.180 147 171 875 mL | - | fluid ounce (Imperial) | fl oz (Imp) | ≡ 1/160 gal (Imp) | = 28.413 062 5 mL | - | fluid ounce (U.S.) | fl oz (US) | ≡ 1/128 gal (US) | = 29.573 529 562 5 mL | - | shot | ≡ 1 US fl oz | = 29.573 529 562 5 mL | - | jigger | ≡ 1 ½ US fl oz | = 44.360 294 343 75 mL | - | gill (U.S.) | gi (US) | ≡ 4 US fl oz | = 118.294 118 25 mL | - | gill (Imperial); Noggin | gi (Imp); nog | ≡ 5 fl oz (Imp) | = 142.065 312 5 mL | - | cup (Canadian) | c (CA) | ≡ 8 fl oz (Imp) | = 227.3045 mL | - | cup (U.S.) | c (US) | ≡ 1/16 gal (US) | = 236.588 236 5 mL | - | cup (metric) | c | ≡ 250 mL | - | breakfast cup | ≡ 10 fl oz (Imp) | = 284.130 625 mL | - | pint (U.S. fluid) | pt (US fl) | ≡ 1/8 gal (US) | = 473.176 473 mL | - | pint (U.S. dry) | pt (US dry) | ≡ 1/4 bu (US lvl) | = 0.550 610 471 357 5 L | - | pint (Imperial) | pt (Imp) | ≡ 1/8 gal (Imp) | = 0.568 261 25 L | - | fifth | ≡ 1/5 US gal | = 0.757 082 356 8 L | - | quart (U.S. fluid) | qt (US) | ≡ 1/4 gal (US fl) | = 0.946 352 946 L | - | quart (U.S. dry) | qt (US) | ≡ 1/32 bu (US lvl) = ¼ gal (US dry) | = 1.101 220 942 715 L | - | quart (Imperial) | qt (Imp) | ≡ ¼ gal (Imp) | = 1.136 522 5 L | - | pottle; quartern | ≡ ½ gal (Imp) = 80 fl oz (Imp) | = 2.273 045 L | - | board-foot | fbm | ≡ 144 cu in | = 2.359 737 216 L | - | gallon (U.S. fluid; Wine) | gal (US) | ≡ 231 cu in | = 3.785 411 784 L | - | gallon (U.S. dry) | gal (US) | ≡ 1/8 bu (US lvl) | = 4.404 883 770 86 L | - | gallon (Imperial) | gal (Imp) | ≡ | = 4.546 09 L | - | beer gallon | beer gal | ≡ 282 cu in | = 4.621 152 048 L | - | peck (U.S. dry) | pk | ≡ ¼ US lvl bu | = 8.809 767 541 72 L | - | peck (Imperial) | pk | ≡ 2 gal (Imp) | = 9.092 18 L | - | bucket (Imperial) | bkt | ≡ 4 gal (Imp) | = 18.184 36 L | - | timber foot | ≡ 1 cu ft | = 28.316 846 592 L | - | cubic foot | cu ft | ≡ 1 ft × 1 ft × 1 ft | = 28.316 846 592 L | - | firkin | ≡ 9 gal (US) | = 34.068 706 056 L | - | bushel (U.S. dry level) | bu (US lvl) | ≡ 2150.42 cu in | = 35.239 070 166 88 L | - | bushel (Imperial) | bu (Imp) | ≡ 8 gal (Imp) | = 36.368 72 L | - | bushel (U.S. dry heaped) | bu (US) | ≡ 1 ¼ bu (US lvl) | = 44.048 837 708 6 L | - | strike (U.S.) | ≡ 2 bu (US lvl) | = 70.478 140 333 76 L | - | strike (Imperial) | ≡ 2 bu (Imp) | = 72.737 44 L | - | kilderkin | ≡ 18 gal (Imp) | = 81.829 62 L | - | sack (U.S.) | ≡ 3 bu (US lvl) | = 105.717 210 500 64 L | - | sack (Imperial); bag | ≡ 3 bu (Imp) | = 109.106 16 L | - | barrel (U.S. dry) | bl (US) | ≡ 105 qt (US) = 105/32 bu (US lvl) | = 115.628 198 985 075 L | - | barrel (U.S. fluid) | fl bl (US) | ≡ 31 ½ gal (US) | = 119.240 471 196 L | - | coomb | ≡ 4 bu (Imp) | = 145.474 88 L | - | barrel (petroleum) | bl | ≡ 42 gal (US) | = 158.987 294 928 L | - | barrel (Imperial) | bl (Imp) | ≡ 36 gal (Imp) | = 163.659 24 L | - | hogshead (U.S.) | hhd (US) | ≡ 2 fl bl (US) | = 238.480 942 392 L | - | seam | ≡ 8 bu (US lvl) | = 281.912 561 335 04 L | - | quarter; pail | ≡ 8 bu (Imp) | = 290.949 76 L | - | hogshead (Imperial) | hhd (Imp) | ≡ 2 bl (Imp) | = 327.318 48 L | - | cord-foot | ≡ 16 cu ft | = 0.453 069 545 472 m³ | - | butt, pipe | ≡ 126 gal (wine) | = 0.476 961 884 784 m³ | - | perch | per | ≡ 16 ½ ft × 1 1/2 ft × 1 ft | = 0.700 841 953 152 m³ | - | cubic yard | cu yd | ≡ 27 cu ft | = 0.764 554 857 984 m³ | - | tun | ≡ 252 gal (wine) | = 0.953 923 769 568 m³ | - | displacement ton | ≡ 35 cu ft | = 0.991 089 630 72 m³ | - | water ton | ≡ 28 bu (Imp) | = 1.018 324 16 m³ | - | freight ton | ≡ 40 cu ft | = 1.132 673 863 68 m³ | - | wey (U.S.) | ≡ 40 bu (US lvl) | = 1.409 562 806 675 2 m³ | - | load | ≡ 50 cu ft | = 1.415 842 329 6 m³ | - | register ton | ≡ 100 cu ft | = 2.831 684 659 2 m³ | - | last | ≡ 80 bu (Imp) | = 2.909 497 6 m³ | - | cord (firewood) | ≡ 8 ft × 4 ft × 4 ft | = 3.624 556 363 776 m³ | - | cubic fathom | cu fm | ≡ 1 fm × 1 fm × 1 fm | = 6.116 438 863 872 m³ | - | acre-inch | ≡ 1 ac × 1 in | = 102.790 153 128 96 m³ | - | acre-foot | ≡ 1 ac × 1 ft | = 1233.481 837 547 52 m³ | - | cubic mile | cu mi | ≡ 1 mi³ | = 4.168 181 825 440 579 584 km³ |
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Angle
| Name of unit | Symbol | Definition | Relation to SI units | - | radian (SI unit) | rad | ≡ 1 rad | - | centesimal second of arc | " | ≡ 1 gr/10000 | ≈ 1.570 796 µrad | - | arcsecond | " | ≡ 1°/3600 | ≈ 4.848 137 µrad | - | centesimal minute of arc | ' | ≡ 1 gr/100 | ≈ 0.157 080 mrad | - | minute of arc | ' | ≡ 1°/60 | ≈ 0.290 888 mrad | - | angular mil | µ | ≡ 2π/6400 rad | ≈ 0.981 748 mrad | - | grad; gradian; gon | gr | ≡ 2π/400 rad = 0.9° | ≈ 15.707 963 mrad | - | degree (of arc) | ° | ≡ π/180 rad | ≈ 17.453 293 mrad | - | sign | ≡ 30° | ≈ 0.523 599 rad | - | octant | ≡ 45° | ≈ 0.785 398 rad | - | sextant | ≡ 60° | ≈ 1.047 198 rad | - | quadrant | ≡ 90° | ≈ 1.570 796 rad |
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Solid angle
| Name of unit | Symbol | Definition | Relation to SI units | - | steradian | sr | (SI derived unit) |
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Mass
| Name of unit | Symbol | Definition | Relation to SI units | - | kilogram | kg | (SI base unit) | - | electron rest mass | me | ≈ 9.109 381 88 × 10−31 ± 72 × 10−39 kg | - | atomic unit of mass | au | ≡ me | ≈ 9.109 381 88 × 10−31 ± 72 × 10−39 kg | - | unified atomic mass unit | amu | ≈ 1.660 538 73 × 10−27 ± 13 × 10−35 kg | - | dalton | Da | ≈ 1.660 902 10 × 10−27 ± 13 × 10−35 kg | - | gamma | γ | ≡ 1 μg | - | point | ≡ 1/100 kt (metric) | = 2 mg | - | mite | ≡ 1/20 gr | = 3.239 945 5 mg | - | mite (metric) | ≡ 1/20 g | = 50 mg | - | grain | gr | ≡ 64.798 91 mg | - | crith | ≈ 89.9349 mg | - | carat (metric) | kt | ≡ 200 mg | - | carat | kt | ≡ 3 1/6 gr | ≈ 205.196 548 333 mg | - | sheet | ≡ 1/700 lb av | = 647.9891 mg | - | scruple (avoirdupois) | s av | ≡ 20 gr | = 1.295 978 2 g | - | pennyweight | dwt; pwt | ≡ 1/20 oz t | = 1.555 173 84 g | - | dram (avoirdupois) | dr av | ≡ 27 11/32 gr | = 1.771 845 195 312 5 g | - | dram (apothecary; troy) | dr t | ≡ 60 gr | = 3.887 934 6 g | - | hyl (CGS unit) | ≡ 1 gee × 1 g × 1 s²/m | = 9.806 65 g | - | ounce (avoirdupois) | oz av | ≡ 1/16 lb | = 28.349 523 125 g | - | assay ton (short) | AT | ≡ 1 mg × 1 sh tn ÷ 1 oz t | ≈ 29.166 667 g | - | ounce (apothecary; troy) | oz t | ≡ 1/12 lb t | = 31.103 476 8 g | - | assay ton (long) | AT | ≡ 1 mg × 1 long tn ÷ 1 oz t | ≈ 32.666 667 g | - | mark | ≡ 8 oz t | = 248.827 814 4 g | - | pound (troy) | lb t | ≡ 5760 grains | = 0.373 241 721 6 kg | - | pound (avoirdupois) | lb av | ≡ 7000 grains | = 0.453 592 37 kg | - | pound (metric) | ≡ 500 g | - | clove | ≡ 8 lb av | = 3.628 738 96 kg | - | stone | st | ≡ 14 lb av | = 6.350 293 18 kg | - | hyl (MKS unit) | ≡ 1 gee × 1 kg × 1 s²/m | = 9.806 65 kg | - | quarter (Imperial) | ≡ 1/4 long cwt = 2 st = 28 lb av | = 12.700 586 36 kg | - | slug; geepound | slug | ≡ 1 gee × 1 lb av × 1 s²/ft | ≈ 14.593 903 kg | - | bag (Portland cement) | ≡ 94 lb av | = 42.637 682 78 kg | - | short hundredweight; cental | sh cwt | ≡ 100 lb av | = 45.359 237 kg | - | long hundredweight | long cwt or cwt | ≡ 112 lb av | = 50.802 345 44 kg | - | bag (coffee) | ≡ 60 kg | = 60 kg | - | quintal (metric) | q | ≡ 100 kg | - | wey | ≡ 252 lb = 18 st | = 114.305 277 24 kg (variants exist) | - | long quarter | ≡ ¼ long tn | = 254.011 727 2 kg | - | kip | kip | ≡ 1000 lb av | = 453.592 37 kg | - | short ton | sh tn | ≡ 2000 lb | = 907.184 74 kg | - | tonne (mts unit) | t | ≡ 1000 kg | - | long ton | long tn or ton | ≡ 2240 lb | = 1016.046 908 8 kg | - | barge | ≡ 22 ½ sh tn | = 20,411.656 65 kg |
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Time
| Name of unit | Symbol | Definition | Relation to SI units | - | second | s | (SI base unit) | - | Planck time | ≡ √(Gℏ/c5) | ≈ 1.351 211 818 × 10−43 s | - | atomic unit of time | au | ≡ a0/(α·c) | ≈ 2.418 884 254 × 10−17 s | - | svedberg | S | ≡ 10−13 s | = 100 fs | - | shake | ≡ 10−8 s | = 10 ns | - | sigma | ≡ 10−6 s | = 1 μs | - | jiffy | ≡ 1/60 s | ≈ 16.666 667 ms | - | jiffy (alternate) | ≡ 1/100 s | ≈ 10 ms | - | helek | ≡ 1/1080 h | ≈ 3.333333 s | - | minute | min | ≡ 60 s | - | moment | ≡ 90 s | ≡ 90 s | - | ke(traditional) | ≡ 1/100 d | ≡ 864 s | - | quarter (of an h) | ke | ≡ 1/96 d | ≡ 900 s | - | hour | h | ≡ 60 min | = 3600 s | - | day | d | ≡ 24 h | = 86 400 s | - | week | wk | ≡ 7 d | = 604 800 s | - | fortnight | ≡ 2 wk | = 1 209 600 s | - | month (hollow) | mo | ≡ 29 d | = 2 505 600 s | - | month | mo | ≡ 30 d | = 2 592 000 s | - | month (full) | mo | ≡ 31 d | = 2 678 400 s | - | year (Calendar) | a or y | ≡ 365 d | = 31 536 000 s | - | year (Gregorian) | a or y | ≡ 365.2425 d | = 31 556 952 s | - | year (Julian) | a or y | ≡ 365.25 d | = 31 557 600 s | - | sidereal year | a or y | ≡ 365.256363 d | = 31 558 149.76 s | - | Olympiad | ≡ 4 a of 365 d | = 1.2614 × 108 s | - | lustre; lustrum | ≡ 5 a of 365 d | = 1.5768 × 108 s | - | octaeteris | ≡ 8 a of 365 d | = 2.522 88 × 108 s | - | decade | ≡ 10 a of 365 d | = 3.1536 × 108 s | - | enneadecaeteris; Metonic cycle | ≡ 110 mo (hollow) + 125 mo (full) = 19 a of 365 d | = 5.996 16 × 108 s | - | Callippic cycle | ≡ 441 mo (hollow) + 499 mo (full) = 76 a of 365.25 d | = 2.398 377 6 × 109 s | - | century (Calendar) | ≡ 100 a of 365 d | = 3.1536 × 109 s | - | century (Julian) | ≡ 100 a of 365.25 d | = 3.155 76 × 109 s | - | Hipparchic cycle | ≡ 4 Callippic cycles - 1 d | = 9.593 424 × 109 s | - | millennium (Calendar) | ≡ 1000 a of 365 d | = 3.1536 × 1010 s | - | millennium (Gregorian) | ≡ 1000 a of 365.2425 d | = 3.155 695 2 × 1010 s | - | millennium (Julian) | ≡ 1000 a of 365.25 d | = 3.155 76 × 1010 s | - | Sothic cycle | ≡ 1461 a of 365 d | = 4.607 409 6 × 1010 s |
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Speed
| Name of unit | Symbol | Definition | Relation to SI units | - | metre per second (SI unit) | m/s | ≡ 1 m/s | - | foot per hour | fph | ≡ 1 ft/h | ≈ 8.466 667 × 10−5 m/s | - | furlong per fortnight | ≡ ½ fur/wk | ≈ 1.663 095 × 10−4 m/s | - | inch per minute | ipm | ≡ 1 in/min | ≈ 4.23 333 × 10−4 m/s | - | foot per minute | fpm | ≡ 1 ft/min | = 5.08 × 10−3 m/s | - | inch per second | ips | ≡ 1 in/s | = 2.54 × 10−2 m/s | - | kilometre per hour | km/h | ≡ 1 km/h | ≈ 2.777 778 × 10−1 m/s | - | foot per second | fps | ≡ 1 ft/s | = 3.048 × 10−1 m/s | - | mile per hour | mph | ≡ 1 mi/h | = 0.447 04 m/s | - | knot | kn | ≡ 1 NM/h = 1.852 km/h | ≈ 0.514 444 m/s | - | knot (Admiralty) | kn | ≡ 1 NM (Adm)/h = 1.853 184 km/h | ≈ 0.514 773 m/s | - | mile per minute | mpm | ≡ 1 mi/min | = 26.8224 m/s | - | mile per second | mps | ≡ 1 mi/s | = 1.609 344 km/s | - | speed of light in vacuum | c | ≡ 2.997 924 58 × 108 m/s |
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Acceleration
| Name of unit | Symbol | Definition | Relation to SI units | - | metre per second squared (SI unit) | m/s² | ≡ 1 m/s² | - | foot per hour per second | fph/s | ≡ 1 ft/h·s | ≈ 8.466 667 × 10−5 m/s² | - | inch per minute per second | ipm/s | ≡ 1 in/min·s | ≈ 4.233 333 × 10−4 m/s² | - | foot per minute per second | fpm/s | ≡ 1 ft/min·s | = 5.08 × 10−3 m/s² | - | galileo | Gal | ≡ 1 cm/s² | = 10−2 m/s² | - | inch per second squared | ips² | ≡ 1 in/s² | = 2.54 × 10−2 m/s² | - | foot per second squared | fps² | ≡ 1 ft/s² | = 3.048 × 10−1 m/s² | - | mile per hour per second | mph/s | ≡ 1 mi/h·s | = 4.4704 × 10−1 m/s² | - | knot per second | kn/s | ≡ 1 kn/s | ≈ 5.144 444 × 10−1 m/s² | - | standard gravity | g | ≡ 9.806 65 m/s² | - | mile per minute per second | mpm/s | ≡ 1 mi/min·s | = 26.8224 m/s² | - | mile per second squared | mps² | ≡ 1 mi/s² | = 1.609 344 × 10³ m/s² |
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Force
| Name of unit | Symbol | Definition | Relation to SI units | - | newton (SI unit) | N | ≡ kg·m/s² | - | atomic unit of force | au | ≡ me·α²·c²/a0 | ≈ 8.238 722 241 × 10−8 N | - | dyne (cgs unit) | dyn | ≡ g·cm/s² | ljm = 10−5 N | - | gravet | ≡ g × 1 g | = 9.806 65 mN | - | poundal | pdl | ≡ 1 lb·ft/s² | = 0.138 254 954 376 N | - | ounce-force | ozf | ≡ g × 1 oz | = 0.278 013 850 953 781 2 N | - | pound-force | lbf | ≡ g × 1 lb | = 4.448 221 615 260 5 N | - | kilogram-force; kilopond; grave | kgf; kp | ≡ g × 1 kg | = 9.806 65 N | - | sthene (mts unit) | sn | ≡ 1 t·m/s² | = 1 kN | - | kip; kip-force | kip; kipf; klbf | ≡ g × 1000 lb | = 4.448 221 615 260 5 kN | - | ton-force | tnf | ≡ g × 1 sh tn | = 8.896 443 230 521 kN |
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Pressure
| Name of unit | Symbol | Definition | Relation to SI units | - | pascal (SI unit) | Pa | ≡ N/m² | = kg/(m·s²) | - | barye (cgs unit) | ≡ 1 dyn/cm² | = 0.1 Pa | - | poundal per square foot | pdl/sq ft | ≡ 1 pdl/sq ft | ≈ 1.488 164 Pa | - | millimetre of water (3.98 °C) | mmH2O | ≈ 999.972 kg/m³ × 1 mm × g | = 9.806 38 Pa (= 0.999972 kgf/m²) | - | pound per square foot | psf | ≡ 1 lb/sq ft × g | ≈ 47.880 259 Pa | - | centimetre of water (3.98 °C) | cmH2O | ≈ 999.972 kg/m³ × 1 cm × g | = 98.0638 Pa | - | torr | torr | ≡ 101 325/760 Pa | ≈ 133.322 368 4 Pa | - | millimetre of mercury | mmHg | ≡ 13 595.1 kg/m³ × 1 mm × g ≈ 1 torr | = 133.322 387 415 Pa | - | inch of water (3.98 °C) | inH2O | ≈ 999.972 kg/m³ × 1 in × g | = 249.082 Pa | - | pièze (mts unit) | pz | ≡ 1000 kg/m·s² | = 1 kPa | - | centimetre of mercury | cmHg | ≡ 13 595.1 kg/m³ × 1 cm × g | = 1.333 223 874 15 kPa | - | foot of water (3.98 °C) | ftH2O | ≈ 999.972 kg/m³ × 1 ft × g | = 2.988 98 kPa | - | inch of mercury | inHg | ≡ 13 595.1 kg/m³ × 1 in × g | = 3.386 388 640 341 kPa | - | pound per square inch | psi | ≡ 1 lb × g / 1 sq in | ≈ 6.894 757 × 10³ Pa | - | foot of mercury | ftHg | ≡ 13 595.1 kg/m³ × 1 ft × g | = 40.636 663 684 091 9 kPa | - | short ton per square foot | ≡ 1 sh tn × g / 1 sq ft | ≈ 95.760 518 kPa | - | atmosphere (technical) | atm | ≡ 1 kgf/cm² | = 98.0665 kPa | - | bar | bar | ≡ 105 Pa | - | atmosphere (standard) | atm | ≡ 101 325 Pa | - | kip per square inch | ksi | ≡ 1 kipf/sq in | ≈ 6.894757 MPa | - | kilogram-force per square millimetre | kgf/mm² | ≡ 1 kgf/mm² | = 9.806 65 MPa |
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Energy or work
| Name of unit | Symbol | Definition | Relation to SI units | - | joule (SI unit) | J | ≡ N·m = W·s = V·A·s | = kg·m²/s² | - | electronvolt | eV | ≡ e × 1 V | ≈ 1.602 176 × 10−19 J | - | rydberg | Ry | ≡ R∞·ℎ·c | ≈ 2.179 872 × 10−18 J | - | hartree | Eh | ≡ me·α²·c² (= 2 Ry) | ≈ 4.359 744 × 10−18 J | - | atomic unit of energy | au | ≡ Eh ≈ 4.359 744 × 10−18 J | - | erg (cgs unit) | erg | ≡ 1 g·cm²/s² | = 10−7 J | - | foot-poundal | ft pdl | ≡ 1 lb·ft²/s² | = 4.214 011 009 380 48 × 10−2 J | - | cubic centimetre of atmosphere; standard cubic centimetre | cc atm; scc | ≡ 1 atm × 1 cm³ | = 0.101 325 J | - | inch-pound force | in lbf | ≡ g × 1 lb × 1 in | = 0.112 984 829 027 616 7 J | - | foot-pound force | ft lbf | ≡ g × 1 lb × 1 ft | = 1.355 817 948 331 400 4 J | - | calorie (20 °C) | cal20 °C | ≈ 4.1819 J | - | calorie (thermochemical) | calth | ≡ 4.184 J | - | calorie (15 °C) | cal15 °C | ≡ 4.1855 J | - | calorie (International Table) | calIT | ≡ 4.1868 J | - | calorie (mean) | calmean | ≈ 4.190 02 J | - | calorie (3.98 °C) | cal3.98 °C | ≈ 4.2045 J | - | litre-atmosphere | l atm; sl | ≡ 1 atm × 1 L | = 101.325 J | - | gallon-atmosphere (U.S.) | US gal atm | ≡ 1 atm × 1 gal (US) | = 383.556 849 013 8 J | - | gallon-atmosphere (Imperial) | US gal atm | ≡ 1 atm × 1 gal (Imp) | = 460.632 569 25 J | - | British thermal unit (thermochemical) | BTUth | ≡ 1 lb/g × 1 calth × 1 °F/°C = 9.489 152 380 4 ÷ 9 kJ | ≈ 1.054 350 kJ | - | British thermal unit (ISO) | BTUISO | ≡ 1.0545 kJ | - | British thermal unit (63 °F) | BTU63 °F | ≈ 1.0546 kJ | - | British thermal unit (60 °F) | BTU60 °F | ≈ 1.054 68 kJ | - | British thermal unit (59 °F) | BTU59 °F | ≡ 1.054 804 kJ | - | British thermal unit (International Table) | BTUIT | ≡ 1 lb/g × 1 calIT × 1 °F/°C | = 1.055 055 852 62 kJ | - | British thermal unit (mean) | BTUmean | ≈ 1.055 87 kJ | - | British thermal unit (39 °F) | BTU39 °F | ≈ 1.059 67 kJ | - | Celsius heat unit (International Table) | CHUIT | ≡ 1 BTUIT × 1 °C/°F | = 1.899 100 534 716 kJ | - | cubic foot of atmosphere; standard cubic foot | cu ft atm; scf | ≡ 1 atm × 1 ft³ | = 2.869 204 480 934 4 kJ | - | kilocalorie; large calorie | kcal; Cal | ≡ 1000 calIT | = 4.1868 kJ | - | cubic yard of atmosphere; standard cubic yard | cu yd atm; scy | ≡ 1 atm × 1 yd³ | = 77.468 520 985 228 8 kJ | - | cubic foot of natural gas | ≡ 1000 BTUIT | = 1.055 055 852 62 MJ | - | horsepower-hour | hp·h | ≡ 1 hp × 1 h | = 2.6845 MJ | - | kilowatt-hour; Board of Trade Unit | kW·h; B.O.T.U. | ≡ 1 kW × 1 h | = 3.6 MJ | - | thermie | th | ≡ 1 McalIT | = 4.1868 MJ | - | therm (U.S.) | ≡ 100 000 BTU59 °F | = 105.4804 MJ | - | therm (E.C.) | ≡ 100 000 BTUIT | = 105.505 585 262 MJ | - | ton of TNT | tTNT | ≡ 1 Gcalth | = 4.184 GJ | - | barrel of oil equivalent | bboe | ≈ 5.8 MBTU59 °F | ≈ 6.12 GJ | - | ton of coal equivalent | TCE | ≡ 7 Gcalth | = 29.3076 GJ | - | ton of oil equivalent | TOE | ≡ 10 Gcalth | = 41.868 GJ | - | quad | ≡ 1015 BTUIT | = 1.055 055 852 62 EJ |
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Power
| Name of unit | Symbol | Definition | Relation to SI units | - | watt (SI unit) | W | ≡ J/s = N·m/s | = kg·m²/s³ | - | lusec | lusec | ≡ 1 L·µmHg/s | ≈ 1.333 224 × 10−4 W | - | foot-pound-force per hour | ft lbf/h | ≡ 1 ft lbf/h | ≈ 3.766 161 × 10−4 W | - | atmosphere cubic centimetre per minute | atm ccm | ≡ 1 atm × 1 cm³/min | = 1.688 75 × 10−3 W | - | foot-pound-force per minute | ft lbf/min | ≡ 1 ft lbf/min | = 2.259 696 580 552 334 × 10−2 W | - | atmosphere–cubic centimetre per second | atm ccs | ≡ 1 atm × 1 cm³/s | = 0.101 325 W | - | BTU (International Table) per hour | BTUIT/h | ≡ 1 BTUIT/h | ≈ 0.293 071 W | - | atmosphere–cubic foot per hour | atm cfh | ≡ 1 atm × 1 cu ft/h | = 0.797 001 244 704 W | - | foot-pound-force per second | ft lbf/s | ≡ 1 ft lbf/s | = 1.355 817 948 331 400 4 W | - | litre-atmosphere per minute | L·atm/min | ≡ 1 atm × 1 L/min | = 1.688 75 W | - | calorie (International Table) per second | calIT/s | ≡ 1 calIT/s | = 4.1868 W | - | BTU (International Table) per minute | BTUIT/min | ≡ 1 BTUIT/min | ≈ 17.584 264 W | - | atmosphere-cubic foot per minute | atm·cfm | ≡ 1 atm × 1 cu ft/min | = 47.820 074 682 24 W | - | square foot equivalent direct radiation | sq ft EDR | ≡ 240 BTUIT/h | ≈ 70.337 057 W | - | litre-atmosphere per second | L·atm/s | ≡ 1 atm × 1 L/s | = 101.325 W | - | horsepower (metric) | hp | ≡ 75 m kgf/s | = 735.498 75 W | - | horsepower (European electrical) | hp | ≡ 75 kp·m/s | = 736 W | - | horsepower (Imperial mechanical) | hp | ≡ 550 ft lbf/s | = 745.699 871 582 270 22 W | - | horsepower (Imperial electrical) | hp | ≡ 746 W | - | ton of air conditioning | ≡ 1 t × 1005 J/kg × 1 °F/K ÷ 10 min | = 844.2 W | - | poncelet | p | ≡ 100 m kgf/s | = 980.665 W | - | BTU (International Table) per second | BTUIT/s | ≡ 1 BTUIT/s | = 1.055 055 852 62 × 10+3 W | - | atmosphere-cubic foot per second | atm cfs | ≡ 1 atm × 1 cu ft/s | = 2.869 204 480 934 4 × 10+3 W | - | ton of refrigeration (IT) | ≡ 1 BTUIT × 1 sh tn/lb ÷ 10 min/s | ≈ 3.516 853 × 10+3 W | - | ton of refrigeration (Imperial) | ≡ 1 BTUIT × 1 lng tn/lb ÷ 10 min/s | ≈ 3.938 875 × 10+3 W | - | boiler horsepower | bhp | ≈ 34.5 lb/h × 970.3 BTUIT/lb | ≈ 9.810 657 × 10+3 W |
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Angular momentum
| Name of unit | Symbol | Definition | Relation to SI units | - | SI unit | J·s | ≡ kg·m²/s | - | atomic unit of action | au | ≡ ℏ = ℎ/2π | ≈ 1.054 571 596 × 10−34 J·s | - | cgs unit | erg·s | = 10−7 J·s |
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Electric current
| Name of unit | Symbol | Definition | Relation to SI units | - | ampere | A | (SI base unit) | - | esu per second; statampere (cgs unit) | esu/s | ≡ (0.1 A·m/s) /c | ≈ 3.335 641 × 10−10 A | - | electromagnetic unit; abampere (cgs unit) | abamp | ≡ 10 A |
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Electric charge
| Name of unit | Symbol | Definition | Relation to SI units | - | coulomb (SI unit) | C | ≡ A·s | - | atomic unit of charge | au | ≡ e | ≈ 1.602 176 462 × 10−19 C | - | statcoulomb; franklin; electrostatic unit (cgs unit) | statC; Fr; esu | ≡ (0.1 A·m) /c | ≈ 3.335 641 × 10−10 C | - | abcoulomb; electromagnetic unit (cgs unit) | abC; emu | ≡ 10 C | - | faraday | F | ≡ 1 mol × NA·e | ≈ 96,485.3383 C |
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Electromotive force
| Name of unit | Symbol | Definition | Relation to SI units | - | volt (SI unit) | V | ≡ kg·m²/(A·s³) | - | abvolt (cgs unit) | abV | ≡ 1 × 10−8 V | - | statvolt (cgs unit) | statV | ≡ c· (1 μJ/A·m) | = 299.792 458 V |
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Electrical resistance
| Name of unit | Symbol | Definition | Relation to SI units | - | ohm (SI unit) | Ω | ≡ V/A | = kg·m²/(A²·s³) |
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Dynamic viscosity
| Name of unit | Symbol | Definition | Relation to SI units | - | pascal second (SI unit) | Pa·s | ≡ N·s/m² | = kg/m·s | - | poise (cgs unit) | P | ≡ 10−1 Pa·s |
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Kinematic viscosity
| Name of unit | Symbol | Definition | Relation to SI units | - | SI unit | m²/s | ≡ m²/s | - | stokes (cgs unit) | St | ≡ 10−4 m²/s |
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Temperature
| Name of unit | Symbol | Relation to SI units | Relation to °C | - | kelvin | K | SI base unit | T= T[°C + 273.15 | - | degree Celsius | °C | T= T[K − 273.15 | - | degree Rankine | °R; °Ra | T= 1.8 × T[K | - | degree Fahrenheit | °F | T= T[K × 1.8 − 459.67 | T= 1.8 × T[°C + 32 |
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See also
- The Unix program units, a useful tool for unit conversion.
- Approximate conversion between English and SI units.
- Temperature conversion formulas for conversions involving additional temperature scales.
- Units conversion by factor-label
- SI
- English unit
- Imperial unit
- U.S. customary unit
External links
- A dictionary of units of measurement
- NIST: Fundamental physical constants — Non-SI units (PDF)
- British law: Units of measurement regulations 1995
- The Unified Code for Units of Measure
- Units, Symbols, and Conversions XML Dictionary
- Unicalc Live web calculator doing units conversion by dimensional analysis
Units of measure | Metrication
Physikalische Größen und ihre Einheiten | Conversión de unidades | Conversion des unités | 単位の換算一覧 | Pozaukładowe jednostki miary | Tabela de conversão de unidades | Conversion of units
"Conversion of units"