Remember that the boiling point of water **depends solely on pressure**. This boiling point calculator finds the pressure at altitude assuming that the pressure at sea level is constant and equal to 1013 hPa (1.013 bar). This approximation is sufficient for this kind of calculations. If you want to find more precise results, check out our air pressure at altitude calculator.

The formulas for boiling point are:

`boiling point = 49.161 × ln(pressure) + 44.932`

`pressure = 29.921 × (1 - 0.0000068753 × altitude)^ 5.2559`

Note that these formulas use specific units:

`boiling point`

is in degrees Fahrenheit (°F);
`pressure`

is expressed in inches of mercury (inHg); and
`altitude`

should be put into the equation in the imperial unit — feet (ft).

However, when using this boiling point at altitude calculator, you can use a wide range of units for each variable.