What temperature does water boil at your altitude?
At sea level water boils at 100 °C (212 °F), but the higher you live the thinner the air, and the lower the boiling point at altitude. In Denver a pan of rolling water sits near 95 °C; in La Paz or Leh it is closer to 88 °C. The bubbles look the same, yet pasta, rice, beans and eggs cook more slowly because the water simply cannot get hotter.
Type your altitude in metres or feet, or press Use my device’s altitude, and the calculator shows the boiling temperature in both scales, how much longer boiling and simmering will take, how far to lower candy and jam temperatures, what a pressure cooker reaches, and the CDC’s boil time for safe drinking water. If you own a barometer you can enter the air pressure instead. Everything runs in your browser.
How to use the Boiling Point at Altitude Calculator
- Choose Altitude (the usual choice) or Air pressure if you have a barometer reading.
- Type your altitude and pick metres or feet, or press Use my device’s altitude and allow location access.
- Optionally enter how many minutes a recipe tells you to boil or simmer something.
- Read the boiling point, the longer cooking time and the notes for candy, pressure cookers and drinking water.
- Use the table to compare other heights, for example before a trip to the mountains.
Boiling Point at Altitude Calculator features
Same maths as the egg timer
The pressure and Antoine-equation formula is identical to the one in the egg boiling timer, so both pages give the same temperature.
Altitude or pressure
Work from height above sea level or from a station pressure in hPa, kPa, inHg, mmHg or psi.
Device altitude
On phones with GPS the browser can fill in your altitude; laptops usually cannot, and the page tells you so.
Cooking-time estimate
A recipe’s boiling or simmering minutes are stretched by a rule-of-thumb factor for the cooler water.
Practical notes
Candy-stage offset, pressure-cooker temperature at 10 and 15 psi, and the CDC rule for boiling drinking water.
How the boiling point is calculated
Water boils when its vapour pressure equals the pressure of the air above it. The calculator first estimates the air pressure at your height with the international standard atmosphere, P = 1013.25 × (1 − 0.0000225577 × h)5.25588 hPa, where h is in metres. It then solves the Antoine equation for water, T = 1730.63 ÷ (8.07131 − log10P) − 233.426, with P in mmHg. At 1,500 m that gives about 846 hPa and 95.0 °C.
A useful rule of thumb falls out of the numbers: the boiling point drops by roughly 1 °C for every 300 m, or about 1 °F for every 500 ft. Weather changes the pressure by a few hPa from day to day, so your real boiling point wanders by a few tenths of a degree around the figure shown.
What a lower boiling point changes in the kitchen
- Boiling and simmering take longer. The page multiplies the time by e0.05 × (100 − T), about 28 % longer at 1,500 m and 65 % longer at 3,000 m. It is a planning estimate: taste the pasta and check that beans are tender.
- Candy and jam. Sugar syrups reach each stage at a lower thermometer reading. Subtract the boiling-point drop from every target, as the candy temperature chart does.
- Eggs. The egg boiling timer uses this same boiling point to lengthen its times.
- Pressure cookers add their gauge pressure to the thinner air, so they still reach about 115–121 °C and cut cooking time sharply; see the pressure cooker time chart.
- Home canning. Never shorten a canning process. Tested recipes give longer water-bath times or higher pressure-canner settings for altitude; follow that table.
Boiling water to make it safe to drink
The CDC’s boil-water advice is to bring clear water to a rolling boil for one minute, or for three minutes at elevations above 6,500 ft (1,981 m), then let it cool. The calculator shows which rule applies at your altitude. Cloudy water should be settled and filtered first. For unit changes such as kPa to psi, use the pressure converter.
Boiling Point at Altitude Calculator FAQ
What is the boiling point of water at my altitude?
Enter your altitude above. As a guide: 100 °C at sea level, about 96.7 °C at 1,000 m, 95.0 °C at 1,500 m, 93.4 °C at 2,000 m and 90.0 °C at 3,000 m.
What temperature does water boil at in Denver?
At about 1,609 m (5,280 ft) water boils at roughly 94.7 °C (202.4 °F), a little higher or lower with the weather.
Why does water boil at a lower temperature at high altitude?
There is less air pressing down on the water, so its vapour pressure matches the air pressure at a lower temperature and it starts to boil sooner.
Does food take longer to cook at high altitude?
Yes, anything cooked in boiling or simmering water. The page estimates how much longer; baking and roasting are affected differently, through faster evaporation and rising.
Can I use the pressure from my weather app?
Usually not. Weather reports give pressure corrected to sea level. You need the actual station pressure from a barometer at your location; otherwise enter your altitude.
How long should I boil water at high altitude to make it safe?
The CDC says one minute at a rolling boil, or three minutes above 6,500 ft (1,981 m).