Air Pressure at Altitude Calculator

Calculate atmospheric pressure at different altitudes using the barometric formula

Calculate Air Pressure at Altitude

Reference pressure at sea level (standard: 101,325 Pa)

Elevation above sea level

Air temperature at the specified altitude

Unit for pressure result

Atmospheric Pressure Results

101325.00
Pa
Pressure at 0 m
Pressure Ratio:1.000
Altitude Class:Sea Level
Boiling Point:100.0°C
Pressure Drop:0.0%

Formula Used: P = P₀ × e^(-gMh/RT)

Altitude: 0.0 m

Temperature: 288.1 K

Sea Level Pressure: 101325 Pa

Classification: Normal atmospheric conditions

Reference Altitudes

Denver, CO
1,655 m (5,430 ft)
~83% sea level pressure
Commercial Aviation
10,000 m (33,000 ft)
~26% sea level pressure
Mount Everest
8,849 m (29,032 ft)
~33% sea level pressure

Example Calculation

Mount Everest Summit

Altitude: 8,849 m

Temperature: -30°C (243.15 K)

Sea Level Pressure: 101,325 Pa

Constants: g=9.81, M=0.0289644, R=8.314

Calculation Steps

1. Convert to SI units

2. Apply barometric formula:

P = 101325 × e^(-9.81×0.0289644×8849/(8.314×243.15))

3. Calculate exponent: -12.58

4. P = 101325 × e^(-12.58)

Result: ~33,700 Pa (0.333 atm)

Physical Constants

g

Gravitational Acceleration

9.80665 m/s²

Standard Earth gravity

M

Molar Mass of Air

0.0289644 kg/mol

Dry air composition

R

Universal Gas Constant

8.31432 J/(mol·K)

Ideal gas law constant

Applications

✈️

Aviation and flight planning

🏔️

Mountaineering and hiking

🌡️

Weather forecasting

🔬

Atmospheric research

🚁

Helicopter performance

Understanding Atmospheric Pressure at Altitude

What is Atmospheric Pressure?

Atmospheric pressure is the force exerted by the weight of air above a given point. As altitude increases, there is less air mass above, resulting in lower atmospheric pressure. This relationship follows the barometric formula.

Why Does Pressure Decrease with Altitude?

  • Less air mass above creates lower pressure
  • Gravitational effects on air molecules
  • Exponential decrease with height
  • Temperature effects on air density

Barometric Formula

P = P₀ × e^(-gMh/RT)

  • P: Pressure at altitude h
  • P₀: Sea level pressure
  • g: Gravitational acceleration (9.81 m/s²)
  • M: Molar mass of air (0.0289644 kg/mol)
  • h: Altitude (m)
  • R: Universal gas constant (8.314 J/mol·K)
  • T: Temperature (K)

Note: This formula assumes constant temperature and gravitational acceleration.

Effects of Reduced Atmospheric Pressure

Physiological Effects

Reduced oxygen availability, altitude sickness, and breathing difficulties at high elevations.

Physical Effects

Lower boiling points, reduced aircraft performance, and changes in fluid behavior.

Practical Applications

Flight planning, weather prediction, mountaineering safety, and engineering design.