Barometric Altitude & Pressure Calculator
Altitude from air pressure (or pressure at an altitude) with the international standard atmosphere.
How to use the Barometric Altitude & Pressure Calculator
- Enter or select: Sea-level pressure (QNH).
- Fill in what you know of: Pressure, Altitude — leave the unknown empty.
- The results (Altitude, Pressure, Standard temperature, Water boiling point) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- h = 44 330.8·(1 − (P/P₀)^0.190263)
- Boiling point: Clausius–Clapeyron with ΔH_vap = 40.66 kJ/mol