Boiling Point at Altitude Calculator

Last updated: April 5, 2026

The Boiling Point at Altitude Calculator finds water's boiling temperature at any elevation using Clausius-Clapeyron. Every 300 m of altitude reduces the boiling point by approximately 1°C — enough to significantly affect cooking times, food safety, and laboratory protocols.

Calculator

Boiling Point at Sea Level°C

Altitudem

Enthalpy of VaporizationJ/mol

Results

Atmospheric Pressure

atm

Atmospheric Pressure

101.33

kPa

Boiling Point at Altitude

100

°C

Boiling Point Drop

°C

Boiling Temperature Ratio

Results

Atmospheric Pressure

atm

Atmospheric Pressure

101.33

kPa

Boiling Point at Altitude

100

°C

Boiling Point Drop

°C

Boiling Temperature Ratio

Water boils when its vapor pressure equals local atmospheric pressure. At sea level that happens at 100°C. At Denver (1,600 m) it happens at approximately 95°C. At Everest base camp (5,364 m) it happens at approximately 83°C — hot enough to feel scalding, but too cool to cook pasta properly or kill all pathogens reliably. The boiling point at altitude calculator gives you the precise boiling temperature for any elevation worldwide.

How Altitude Affects Boiling Point

Atmospheric pressure decreases with altitude following the barometric formula. Reduced pressure means water molecules need less thermal energy to escape into vapor — so the liquid boils at a lower temperature. The relationship using the Clausius-Clapeyron equation:

T₂ = 1 / [1/T₁ − (R/ΔH_vap) × ln(P₂/P₁)]

where T₁ = 373.15 K (100°C at sea level), P₁ = 101,325 Pa, ΔH_vap = 40,700 J/mol for water, R = 8.314 J/(mol·K), and P₂ is the local atmospheric pressure at your altitude. Use this online calculator for any elevation. The boiling point calculator covers other substances and solute effects.

Boiling Point of Water at Key Altitudes

Sea level (0 m): 100.0°C / 212.0°F
Mexico City (2,250 m): approximately 92.5°C / 198.5°F
Denver, CO (1,610 m): approximately 95.0°C / 203.0°F
La Paz, Bolivia (3,640 m): approximately 87.5°C / 189.5°F
Everest Base Camp (5,364 m): approximately 83°C / 181°F
Summit of Everest (8,849 m): approximately 70°C / 158°F

Practical Implications: Cooking and Food Safety at Altitude

Lower boiling point means longer cooking times for boiled foods: pasta takes 1–2 extra minutes per 1,000 m of altitude; hard-boiled eggs take 2–3 minutes longer at 3,000 m; dried beans may require a pressure cooker above 2,500 m for reliable softening. Food safety: the USDA pasteurization temperature for eggs is 71°C — achieved at all altitudes. However, water at 83°C (Everest base camp) will not achieve the 100°C sterilization effectiveness assumed in standard food safety guidelines. Pressure cookers restore sea-level boiling temperatures at any altitude by raising internal pressure above ambient. The boiling point elevation calculator covers dissolved solute effects on boiling point.

Laboratory Applications

In chemistry and biology labs at altitude: reflux temperatures are lower than at sea level; distillation fractions shift; autoclave sterilization requires higher pressure settings to achieve equivalent temperatures. Any laboratory protocol specifying a temperature based on boiling point (e.g., "heat to boiling") should be adjusted for local altitude when precision matters.

Visual Analysis

How It Works

Enter elevation in meters or feet. Atmospheric pressure is estimated using the barometric formula: P = 101325 × (1 − 2.25577×10⁻⁵ × h)^5.25588 Pa. Boiling point: T₂ = 1 / [1/373.15 − (8.314/40700) × ln(P/101325)] Kelvin, converted to °C and °F. Cooking time adjustment shown for common foods.

Understanding Your Results

The adjusted boiling point shows the temperature at which the liquid will boil at the given altitude. A lower boiling point means water and other liquids will boil at lower temperatures, which affects cooking times (food takes longer to cook because the temperature is lower) and industrial processes. The boiling point decrease shows how many degrees the boiling point has dropped compared to sea level. At very high altitudes such as Mount Everest (~8,849 m), water boils around 70°C, making it impossible to cook many foods properly.

Worked Examples

Boiling Water in Denver, Colorado (1,609 m)

Inputs

bp normal100

altitude1609

delta h40660

Results

pressure atm0.8265

bp adjusted94.88

bp drop5.12

In Denver (the 'Mile High City'), water boils at approximately 94.9°C instead of 100°C, which is why baking recipes often require altitude adjustments.

Boiling Water on Mount Everest (8,849 m)

Inputs

bp normal100

altitude8849

delta h40660

Results

pressure atm0.3499

bp adjusted69.84

bp drop30.16

At the summit of Mount Everest, water boils at about 70°C. At this temperature, it is impossible to properly cook pasta or boil eggs, which is why climbers rely on pressure cookers or pre-cooked food.

Frequently Asked Questions

Water's boiling point decreases approximately 0.34°C per 100 meters (or about 1°C per 300 meters) of altitude. Key reference points: sea level 100°C; 1,000 m altitude approximately 96.7°C; 2,000 m approximately 93.3°C; 3,000 m approximately 90°C; 4,000 m approximately 86.7°C; 5,000 m approximately 83.4°C; 8,849 m (Everest summit) approximately 70°C. The relationship is not perfectly linear — the Clausius-Clapeyron equation gives a slightly curved relationship because the enthalpy of vaporization of water decreases with temperature. For cooking and safety purposes, the 1°C per 300 m rule is accurate enough at typical inhabited elevations.

Since water boils at a lower temperature at altitude, boiling-based cooking takes longer. General adjustments: pasta — add 1 minute per 500 m above sea level; hard-boiled eggs — add 1 minute per 300 m; dried beans — add 10–25% more cooking time above 1,500 m (or use a pressure cooker); cake and quick bread mixes — reduce leavening agents by 15–25% and increase liquid slightly (the lower boiling point causes gases to expand more in baked goods). The USDA provides specific altitude adjustment tables for boiling, pressure canning, and baking. For precision cooking, a calibrated thermometer and pressure cooker are the most effective tools at elevations above 2,000 m.

Yes — water boiled at altitude is safe for drinking. The CDC and WHO recommend bringing water to a rolling boil for 1 minute at elevations below 2,000 m, and for 3 minutes above 2,000 m. The reason for the longer boil at altitude is that the lower boiling temperature (e.g., 90°C at 3,000 m) requires more exposure time to achieve equivalent pathogen inactivation to 100°C boiling at sea level. All common waterborne pathogens (Giardia, Cryptosporidium, bacteria, viruses) are inactivated by water maintained at 70°C for 1–3 minutes — well above the boiling point at any inhabited altitude. A rolling boil is a reliable disinfection indicator at all altitudes where humans can survive.

A liquid boils when its vapor pressure equals the surrounding atmospheric pressure. At higher altitudes, atmospheric pressure is lower because there is less air column above you. Water reaches equilibrium between liquid and vapor at a lower temperature when the external pressure is lower — requiring less thermal energy to drive evaporation. This is a direct consequence of the Clausius-Clapeyron equation, which describes the relationship between vapor pressure and temperature for any substance. At sea level, water's vapor pressure equals 101,325 Pa at 100°C. At 3,000 m, atmospheric pressure is approximately 70,100 Pa — and water's vapor pressure reaches this lower value at approximately 90°C.

Yes — a pressure cooker raises internal pressure above ambient, which raises the boiling point of water back to sea-level equivalents or above. A standard pressure cooker at 15 psi (103 kPa) gauge pressure operates at approximately 121°C (250°F) at sea level. At high altitude, the absolute internal pressure is lower (because ambient pressure is lower), but the effective cooking temperature still significantly exceeds the unpressurized boiling point. At 3,000 m altitude with a 15 psi pressure cooker, internal temperature reaches approximately 110–115°C — much closer to sea-level performance than open boiling. Pressure cooking at altitude is particularly important for: canning (to achieve sterilization temperatures); cooking dried legumes (which can remain hard at low boiling temperatures); and reducing very long cooking times in high-altitude environments.

At 2,000 meters altitude, standard atmospheric pressure is approximately 79,495 Pa (79.5 kPa or 0.785 atm) — about 21.5% lower than sea-level pressure of 101,325 Pa. The barometric formula gives: P = 101325 × (1 − 2.25577×10⁻⁵ × h)^5.25588, where h = height in meters. Reference values: 0 m = 101,325 Pa; 500 m = 95,460 Pa; 1,000 m = 89,876 Pa; 1,500 m = 84,556 Pa; 2,000 m = 79,495 Pa; 3,000 m = 70,108 Pa; 4,000 m = 61,640 Pa; 5,000 m = 54,020 Pa. These are standard atmosphere values — actual pressure varies with weather and temperature.

Sources & Methodology

Atkins, P., de Paula, J. (2014). Atkins' Physical Chemistry, 10th ed. USDA (2022). High-Altitude Cooking and Food Safety. NASA (2023). Standard Atmosphere Model.

How helpful was this calculator?

Be the first to rate!

Related Calculators

Dilution Calculator

Solution Concentration Calculators

TDS Calculator

Solution Concentration Calculators

Mixing Ratio Calculator

Solution & Mixture Calculators

Calorimetry Calculator

Thermodynamics Calculators

Wine for Party Calculator

Beverage Calculators for Parties

Champagne for Party Calculator

Beverage Calculators for Parties

How It Works

Understanding Your Results

Worked Examples

Boiling Water in Denver, Colorado (1,609 m)

Inputs

bp normal100

altitude1609

delta h40660

Results

pressure atm0.8265

bp adjusted94.88

bp drop5.12

In Denver (the 'Mile High City'), water boils at approximately 94.9°C instead of 100°C, which is why baking recipes often require altitude adjustments.

Boiling Water on Mount Everest (8,849 m)

Inputs

bp normal100

altitude8849

delta h40660

Results

pressure atm0.3499

bp adjusted69.84

bp drop30.16

Frequently Asked Questions