Chemistry
Boiling Point at Altitude Calculator
See how the boiling point of water falls as you climb, using the standard-atmosphere pressure model.
Your inputs
Change any value to update the result instantly.
Water boils at
99.01 °C
In fahrenheit
210.23 °F
Air pressure
28.855 inHg
Air pressure
977.2 mbar
Drop from sea level
0.99 °C
Cooking note
Close to normal sea-level cooking times
Altitude is in feet and pressure in inches of mercury, matching the standard-atmosphere correlation. Real weather moves the pressure a little either way.
What this calculator does
Estimates the boiling point of water at a given altitude using the standard-atmosphere pressure correlation.
What your result means
The temperature at which water boils where you are; food takes longer to cook as this falls.
Formula and working
P(inHg) = 29.921 × (1 − 0.0000068753h)^5.2559; T_b(°F) = 49.161 × ln(P) + 44.932
- 1
Collect the inputs
Altitude above sea level = 1,000 ft
- 2
Apply the formula
P(inHg) = 29.921 × (1 − 0.0000068753h)^5.2559; T_b(°F) = 49.161 × ln(P) + 44.932
- 3
Result
Water boils at = 99.01 °C
Frequently asked questions
Symbols and assumptions
- h
- Altitude in feet
- P
- Air pressure in inHg
- T_b
- Boiling temperature
- • Standard atmosphere conditions.
- • Altitude in feet and pressure in inches of mercury, as the correlation requires.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Weather systems shift local pressure, so the real boiling point moves a degree or so either way.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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