Food and cooking heat

Water Boiling Point vs Altitude Calculator

Higher elevations usually have lower atmospheric pressure, so pure water boils at a lower temperature. Enter an altitude to estimate the local boiling point under a standard-atmosphere model.

Estimate boiling point

Why altitude changes boiling point

A liquid boils when its vapour pressure reaches the pressure acting on its surface. As elevation increases, atmospheric pressure generally decreases. Water therefore reaches the boiling condition at a lower temperature.

Why turning up the burner does not restore 100 °C

Once water is boiling at a given ambient pressure, extra burner power mainly increases the rate of vaporisation. It does not force an open pot of water to remain at 100 °C when the local boiling point is lower.

Why this matters in cooking

USDA guidance notes that boiling and simmering occur at lower temperatures at high altitude, so some cooking processes take longer. Recipe adjustment and food-safety decisions should follow authoritative guidance for the food and cooking method rather than this physical estimate alone.

Sources and further reading

USDA FSIS: High Altitude Cooking - practical context for lower boiling temperatures and cooking adjustments.
NIST Chemistry WebBook: Fluid Properties - thermophysical-property reference resources.