Stagnation pressure is the pressure at a stagnation point in a fluid flow, where the kinetic energy is converted into pressure energy.

It is the pressure a fluid retains when brought to rest isentropically.

Assuming an isentropic process, the stagnation pressure ratio can be calculated:

$P/p\; =\; (T/t)^\{\backslash gamma/(\backslash gamma-1)\}\backslash ,$

where:

$P\; =\backslash ,$ stagnation (or total) pressure aka To1

$p\; =\backslash ,$ static pressure

$T\; =\backslash ,$ stagnation (or total) temperature in kelvins

$t\; =\backslash ,$ static temperature in kelvins

$\backslash gamma\backslash \; =\backslash ,$ ratio of specific heats

Stagnation quantities (e.g. stagnation temperature, stagnation pressure) are frequently used in jet engine performance calculations.

Pitot tubes are used to measure stagnation (or total) pressure. A combined pitot/static tube is used on aircraft to determine flight speed.