Boiling Point at Altitude Calculator
Calculate the estimated boiling point of water at different elevations. Enter altitude in feet or meters and instantly see the boiling temperature in Celsius and Fahrenheit.
Calculate Boiling Point
This calculator estimates the normal boiling point of pure water using standard-atmosphere pressure at the entered altitude. Actual weather pressure and dissolved substances can change the real boiling temperature.
At standard sea-level pressure, pure water boils at approximately 100°C or 212°F.
What Is a Boiling Point at Altitude Calculator?
A Boiling Point at Altitude Calculator estimates the temperature at which pure water boils at a selected elevation. As altitude increases, atmospheric pressure generally decreases, so water can boil at a lower temperature.
At standard sea-level pressure, pure water boils at approximately 100°C (212°F). At higher elevations, the atmospheric pressure is lower and the boiling temperature decreases.
How to Use the Boiling Point at Altitude Calculator
You only need the altitude or elevation of the location to get an estimated boiling temperature.
Enter the Altitude
Enter the elevation of the location where you want to estimate the boiling point.
Select Feet or Meters
Choose feet or meters. The calculator automatically converts units internally.
Calculate the Boiling Point
Click the button to see the estimated boiling point in both Celsius and Fahrenheit, along with estimated atmospheric pressure.
Why Does Boiling Point Change with Altitude?
A liquid boils when its vapor pressure reaches the surrounding pressure. Atmospheric pressure therefore has a direct effect on boiling temperature.
At higher elevations there is generally less atmospheric pressure. Water does not need to reach as high a temperature before its vapor pressure matches the surrounding air pressure, so it boils at a lower temperature.
Higher Altitude → Lower Atmospheric Pressure → Lower Boiling Point
The relationship is not perfectly linear. For improved estimation, this calculator first estimates atmospheric pressure using the standard atmosphere and then solves a vapor-pressure equation for the corresponding boiling temperature.
How Is Boiling Point at Altitude Calculated?
The calculator first estimates atmospheric pressure for the entered elevation using a standard-atmosphere approximation.
P = 101325 × (1 − 2.25577 × 10−5 × h)5.25588
Here, P is atmospheric pressure in pascals and h is altitude in meters. This approximation is appropriate for ordinary elevations in the lower atmosphere.
The calculator then uses the estimated pressure with the Antoine vapor-pressure equation for water to estimate the temperature where water vapor pressure matches the atmospheric pressure.
log10(P) = A − B / (C + T)
For the temperature range relevant to ordinary water boiling conditions, the calculator uses suitable Antoine constants and converts the atmospheric pressure to mmHg before solving for temperature.
Boiling Point at Different Altitudes
The following values are approximate and can vary with actual atmospheric pressure.
| Altitude | Approx. Boiling Point °C | Approx. Boiling Point °F |
|---|---|---|
| 0 ft / 0 m | 100°C | 212°F |
| 1,000 ft / 305 m | About 99°C | About 210°F |
| 2,500 ft / 762 m | About 97°C | About 207°F |
| 5,000 ft / 1,524 m | About 95°C | About 203°F |
| 7,500 ft / 2,286 m | About 92°C | About 198°F |
| 10,000 ft / 3,048 m | About 90°C | About 194°F |
Boiling Point Example
Suppose you are at an elevation of 5,000 feet, or about 1,524 meters above sea level.
Atmospheric pressure at this elevation is substantially lower than standard sea-level pressure. The estimated boiling point of pure water is therefore around 95°C, or approximately 203°F.
What Affects the Boiling Point of Water?
Altitude
Higher elevation normally means lower atmospheric pressure, which lowers the boiling point of water.
Atmospheric Pressure
Boiling temperature is directly related to surrounding pressure. Daily weather changes can therefore slightly change the actual result.
Dissolved Substances
Salt and other dissolved substances can alter the boiling point, so pure water and solutions may not boil at exactly the same temperature.
Pressure Environment
A sealed pressure cooker raises pressure above normal atmospheric pressure, allowing water to boil at a higher temperature.
Why Does High-Altitude Cooking Take Longer?
At high altitude, water can reach its boiling point at a lower temperature. Although the water may be visibly boiling, its temperature can still be lower than boiling water at sea level.
Foods that depend heavily on boiling or simmering may therefore require different cooking times or recipe adjustments at higher elevations.
Boiling Point at Altitude Calculator FAQs
At standard atmospheric pressure of 1 atmosphere, pure water boils at approximately 100°C or 212°F.
Yes. Atmospheric pressure generally decreases as altitude increases. Lower pressure allows water to boil at a lower temperature.
Under standard atmospheric conditions, the boiling point of pure water at 5,000 feet is roughly 95°C, or about 203°F. Actual values can vary slightly with weather pressure.
At approximately 10,000 feet above sea level, pure water boils near 90°C, or roughly 194°F, under typical standard-atmosphere conditions.
A liquid boils when its vapor pressure equals the surrounding pressure. Because atmospheric pressure decreases with elevation, this condition occurs at a lower temperature at higher altitudes.
Yes. Atmospheric pressure changes with weather, so the actual boiling point can differ slightly from an altitude-only estimate.
Yes. If the surrounding pressure is greater than standard atmospheric pressure, water can remain liquid above 100°C before boiling. Pressure cookers are a common example.