In short: water boils at a lower temperature the higher you go, because there's less air pressing down on it. At sea level it boils at 100°C (212°F); in Denver (5,280 ft) that's about 94.7°C (202.4°F); on Mount Everest's summit, roughly 70.3°C (158.5°F). Use the calculator above for any elevation, or the chart and table to see the full curve.
These figures are planning aids based on the standard atmosphere. For canning and food-safety timing, follow your equipment manufacturer's or your local extension office's official altitude adjustments.
How to calculate the boiling point of water at altitude
Water boils when its vapor pressure — the pressure of the water molecules trying to escape into the air — equals the pressure of the atmosphere pushing back down on it. At sea level, standard atmospheric pressure is high enough that water must reach 100°C before its vapor pressure can match it. Go up in elevation, and the air thins out, so water needs less heat to win that contest. The calculation happens in two steps:
Step 2: solve the Antoine equation for the temperature at which water's vapor pressure equals that value Step 1 is the barometric formula for the standard atmosphere (elevation in meters). Step 2 uses the Antoine equation for water, which relates vapor pressure directly to temperature — the calculator solves it algebraically for temperature rather than pressure.
Worked example. Take an elevation of 7,000 ft (2,133.6 m). The barometric formula gives a pressure of 78.19 kPa. Converting to millimeters of mercury (78.19 × 7.50062 = 586.6 mmHg) and solving the Antoine equation, log₁₀(586.6) = 2.7684, so T = 1730.63 ÷ (8.07131 − 2.7684) − 233.426 = 92.92°C, or 199.25°F. That's about 7°C (13°F) cooler than sea level.
Why two equations, not one. Altitude doesn't set the boiling point directly — it sets the air pressure, and pressure sets the boiling point. That's also why weather (a passing high- or low-pressure system) shifts the boiling point slightly at a fixed elevation, and why the same principle lets a sealed pressure cooker boil water above 100°C without going anywhere higher.
Why lower pressure lowers the boiling point
Think of boiling as a tug-of-war. Heat energy pushes water molecules to escape into vapor; atmospheric pressure pushes back, keeping them liquid. At sea level, the atmosphere presses down with about 14.7 psi (101.3 kPa) — roughly the weight of the entire column of air above you — so water needs to reach 100°C before enough molecules have enough energy to overcome it. Climb to 10,000 ft and that column of air above you is thinner, pressing down with only about 10.1 psi (69.7 kPa). Water wins the tug-of-war at a much lower temperature, around 89.9°C (193.8°F).
This is also why the effect isn't perfectly linear: pressure itself falls off exponentially with elevation (thick air near the ground, thin air higher up), so the boiling-point drop is steepest near sea level and gradually tapers as you climb. The chart above traces that exact curve using the standard atmosphere model.
Boiling point of water by elevation
A quick-reference version of the calculator's default range, from sea level to 14,000 ft. Use the tool above for exact figures at any elevation, in feet or meters.
| Elevation | Boiling point | Pressure (kPa) | Pressure (psi) |
|---|---|---|---|
| Sea level (0 ft) | 100.00°C / 212.0°F | 101.33 | 14.70 |
| 2,000 ft | 97.98°C / 208.4°F | 94.21 | 13.66 |
| 4,000 ft | 95.96°C / 204.7°F | 87.51 | 12.69 |
| 5,280 ft (Denver) | 94.66°C / 202.4°F | 83.43 | 12.10 |
| 6,000 ft | 93.93°C / 201.1°F | 81.20 | 11.78 |
| 8,000 ft | 91.90°C / 197.4°F | 75.26 | 10.92 |
| 10,000 ft | 89.87°C / 193.8°F | 69.68 | 10.11 |
| 12,000 ft | 87.83°C / 190.1°F | 64.44 | 9.35 |
| 14,000 ft | 85.79°C / 186.4°F | 59.52 | 8.63 |
Quick reference: boiling point in well-known places
Boiling points for some commonly searched elevations, computed the same way as the calculator above.
| Location | Elevation | Boiling point |
|---|---|---|
| Sea level | 0 ft / 0 m | 100.0°C / 212.0°F |
| Salt Lake City, UT | 4,226 ft / 1,288 m | 95.7°C / 204.3°F |
| Denver, CO | 5,280 ft / 1,609 m | 94.7°C / 202.4°F |
| Flagstaff, AZ | 6,910 ft / 2,106 m | 93.0°C / 199.4°F |
| Mexico City, MX | 7,350 ft / 2,240 m | 92.6°C / 198.6°F |
| Aspen, CO | 7,908 ft / 2,410 m | 92.0°C / 197.6°F |
| Leadville, CO | 10,152 ft / 3,094 m | 89.7°C / 193.5°F |
| Everest Base Camp | 17,600 ft / 5,364 m | 82.1°C / 179.8°F |
| Mount Everest summit | 29,032 ft / 8,849 m | 70.3°C / 158.5°F |
Worked examples
Boiling pasta in Denver
94.7°C
At 5,280 ft, water boils at about 94.7°C (202.4°F) instead of 100°C. The water is still boiling vigorously, but at a lower temperature, so pasta and other boiled foods typically need a few extra minutes.
Camping at 10,000 ft
89.9°C
A backcountry camp at 10,000 ft sees water boil around 89.9°C (193.8°F). Combined with lower atmospheric pressure, this is also why dried beans and rice take noticeably longer to soften without a pressure cooker.
A cup of tea at Everest Base Camp
82.1°C
At 17,600 ft, water boils at just 82.1°C (179.8°F) — noticeably cooler than a normal cup of tea. Climbers at higher camps rely on pressure cookers or accept much longer cooking times.
What else affects the boiling point
Dissolved solids. Salt, sugar, and other dissolved solutes raise the boiling point slightly — a phenomenon called boiling-point elevation. A heavily salted pot of pasta water boils a fraction of a degree higher than plain water at the same elevation, though the effect is small at typical kitchen concentrations.
Day-to-day weather. A passing high- or low-pressure weather system can shift local air pressure by roughly ±1–3 kPa, nudging the boiling point by a few tenths of a degree at any fixed elevation. This calculator uses the standard atmosphere — the long-term average — rather than today's forecast.
Pressure cookers. Sealing a pot and letting pressure build lets water boil well above 100°C regardless of elevation, which is exactly why they're recommended at altitude for foods that need higher heat, like dried beans. See our energy-to-boil-water calculator for how much heat is needed to reach a boil in the first place.
Frequently asked questions
Why does water boil at a lower temperature at high altitude?
Water boils when its vapor pressure equals the surrounding atmospheric pressure. Air pressure drops as elevation increases, so water needs less heat to reach that balance point. At sea level the air pushes back hard enough to hold water to about 100°C (212°F); on a mountain, thinner air lets it boil at a noticeably lower temperature.
At what elevation does water boil at 200°F?
Water boils at about 200°F (93.3°C) at roughly 6,600 feet (2,010 m) of elevation, based on the standard atmosphere. This is why many high-altitude baking charts use 200°F as a reference point for cities in that elevation band.
What temperature does water boil at in Denver, Colorado?
In Denver, at about 5,280 feet (1,609 m), water boils at approximately 94.7°C (202.4°F) instead of 100°C (212°F) at sea level — a difference of about 5.3°C (9.6°F).
Does food really take longer to cook at high altitude?
Yes, for foods cooked in boiling water. Since the water itself is cooler, it transfers heat more slowly even though it is still boiling vigorously, so pasta, eggs, rice, and dried beans typically need extra time at elevation. Baking is affected too, but through lower air pressure and faster moisture loss rather than boiling point alone.
How much does the boiling point drop per 1,000 feet of elevation?
Near sea level, the boiling point drops by roughly 1.8°F (about 1°C) for every 1,000 feet of elevation gained. The relationship isn't perfectly linear — the drop is slightly smaller at very high elevations — which is why this calculator solves the barometric and Antoine equations directly instead of using a flat rate.
Can a pressure cooker fix the altitude problem?
Yes. A pressure cooker seals in steam and raises the internal pressure above the surrounding air, which lets water inside boil above 100°C (212°F) regardless of elevation. That is why pressure cookers are commonly recommended at high altitude for foods like dried beans that need higher heat to cook through.
Sources & references
- NOAA, NASA & United States Air Force (1976). U.S. Standard Atmosphere, 1976.
- Antoine, C. (1888). Tensions des vapeurs: nouvelle relation entre les tensions et les températures. Comptes Rendus, 107, 681–684.
- National Institute of Standards and Technology (NIST). Chemistry WebBook — Thermophysical properties of water.
John Mac, PE
Water Systems Specialist · Austin, Texas
Texas-licensed Professional Engineer with 13+ years in residential water systems and 180+ completed projects. Writes and reviews the calculators on watercalculator.us. Read full bio
Texas PE (2016) · BS Civil Engineering, Hydraulics (2013)