Standard pressure
Airfield elevation 5,500 ft with QNH 1013.25 hPa gives a pressure altitude of 5,500 ft.
ALTITUDE CALCULATIONS
Pressure altitude calculator
Find what the altimeter indicates on the standard pressure setting.
Airfield & weather
Live calculationUse the published airfield elevation and current QNH.
ft MSL
Use −1,500 to 20,000 ft.hPa
Use 800–1,100 hPa.Pressure units
Pressure altitude
LIVE RESULTStandard-pressure indication5,500 ft
Altimeter set to QNE / standard pressure
QNH 1013.25 hPaStandard setting (QNE) 1013.25 hPa
THREE ALTIMETER REFERENCES
How it works QNH, QNE & QFE at a glance.
QNH is referenced to mean sea level, QFE to the airfield. The dotted QNE datum moves relative to QNH as the pressure setting changes.
Swipe diagram to see all three settings →
QNH1013.25 hPa
Reads 5,500 ft MSL at the airfield.
QNE1013.25 hPa
Reads 5,500 ft pressure altitude at the airfield.
QFE827.42 hPa
Reads approximately 0 ft at the airfield reference datum.
THE METHOD
What pressure altitude means.
Pressure altitude is the altitude indicated when an altimeter is set to 1013.25 hPa (29.92 inHg), the standard pressure setting known as QNE. Enter the published airfield elevation and current QNH; the calculator estimates local airfield pressure using a standard-atmosphere altimeter model and derives the corresponding pressure altitude.
Standard-atmosphere relationship
Airfield pressure ≈ QNH × (1 − L × elevation / T₀)^5.25588Enter QNH in hPa or inHg. Pressure values display to two decimal places and altitude to the nearest foot; calculations retain full precision. The diagram is illustrative rather than a scale drawing of physical pressure layers.
WORKED EXAMPLES01 02
Pressure altitude in practice.
Lower pressure
Airfield elevation 5,500 ft with QNH 1000 hPa gives a pressure altitude of approximately 5,850 ft.
Pressure altitude questions
What is pressure altitude?+
Pressure altitude is the altitude indicated when the altimeter is set to the standard QNE setting of 1013.25 hPa or 29.92 inHg.
Why can pressure altitude differ from airfield elevation?+
Airfield elevation is fixed, while pressure altitude changes with atmospheric pressure. Lower QNH generally produces a higher pressure altitude.
Can I enter QNH in inches of mercury?+
Yes. Select inHg and enter a value from 23.62 to 32.48. The calculator converts it to hPa internally.
A planning aid. Use published data for flight.
QFE is estimated from QNH with a standard-atmosphere model. Check current official pressure information and local altimeter-setting procedures before flight.