The triple point of water or any substance is the combination of temperature and pressure at which it exists in its solid, liquid, and gaseous state all at once, in equilibrium.

The temperature of the triple point of water is a commonly used physical constant which is used to define temperature scales and calibrate temperature-measuring systems.

By definition, the temperature of the triple point of water is 273.16 K, or 0.01 °C.

Poent tric'hement | Punt triple | Trojný bod | Tripelpunkt | Triple point | Punto triple | Point triple | 삼중점 | Þrípunktur | Punto triplo | נקודה משולשת | Tripelpunt | 三重点 | Punkt potrójny | Ponto triplo | Тройная точка | Trojný bod | Trojna točka | Kolmoispiste | Trippelpunkt | Điểm ba trạng thái | 三相点