Boiling Point at Altitude Calculator

Find the boiling point of water at different altitudes above sea level. This calculator uses the barometric formula and Clausius-Clapeyron equation. Essential for high-altitude cooking and outdoor recipes.

Height above sea level

PRESSURE AT ALTITUDE: P = P₀ × (1 - 2.256×10⁻⁵ × h_m)^5.25588 Where: - P₀ = 101.325 kPa (sea level) - h_m = altitude in meters BOILING POINT FROM PRESSURE: Using Clausius-Clapeyron (inverted): T₂ = 1 / [1/Tb - (R/ΔHvap) × ln(P/P₀)] For water: Tb = 373.15 K, ΔHvap = 40.7 kJ/mol APPROXIMATE RELATIONSHIPS: - 1,000 ft: 99.5°C (211°F) - 3,000 ft: 97°C (207°F) - 5,000 ft: 95°C (203°F) - 10,000 ft: 90°C (194°F)
Example: Denver, CO elevation (~5,280 ft) Input: 5280 feet Calculate pressure: ~0.83 atm (83.5 kPa) Use Clausius-Clapeyron: new T ≈ 95.3°C Water boils at ~95°C (203°F) instead of 100°C. Pasta takes longer! At 14,000 ft (Colorado peaks): Pressure ~0.6 atm Water boils at ~87°C Need pressure cooker for normal cooking times

How does altitude affect boiling point?

Lower air pressure at altitude means water boils at a lower temperature. At sea level (1 atm), water boils at 100°C (212°F). At 5,000 feet (~0.8 atm), it boils at ~95°C. At 10,000 feet (~0.7 atm), it boils at ~90°C. At 20,000 feet, it's below 80°C. This is why pasta takes longer at altitude.

Why does cooking take longer at altitude?

Lower boiling temperature = less heat energy available for cooking. Foods cook slower because the water is cooler. A recipe that simmers at 100°C simmers at only ~90°C at 10,000 ft. Meat proteins coagulate, vegetables soften, and starches gelatinize at lower temperatures—cooking works, but timing needs adjustment.

What is the relationship between altitude and pressure?

Pressure decreases exponentially with altitude using the barometric formula: P = P₀ × exp(-Mgh/RT). At ~5,500 m (18,000 ft), pressure is half sea level. At 100 km, it's virtually zero. Near sea level: pressure drops about 1 inch-Hg (3.4 kPa) per 1,000 feet gain.

At what altitude does cooking significantly change?

Minor effects start around 3,000 ft. At 5,000 ft (most mountain towns), add 5-10 minutes for pasta, reduce baking temperatures by 25°F. At 8,000+ ft, significant recipe adjustments needed. Above 12,000 ft, pressure cookers are highly recommended.

What temperature does water actually boil at my altitude?

Our calculator gives exact values. At 1,000 ft: ~99.5°C. At 3,000 ft: ~98°C. At 5,000 ft: ~95°C. At 8,000 ft: ~92°C. At 10,000 ft: ~90°C. At 14,000 ft (Denver): ~87°C. At 20,000 ft: ~80°C.

How do I use a pressure cooker at altitude?

Pressure cookers overcome altitude limitations by raising internal pressure above 1 atm. At 8,000 ft, a pressure cooker can bring water to ~115-120°C! This brings cooking times back to near normal. Essential above 8,000 ft, highly recommended above 5,000 ft.

🧮
Boiling Point Calculator
🧮
Boiling Point Elevation Calculator
🧮
Air Pressure Calculator
🧮
Pressure Calculator