Altimeter Correction Calculator
Convert between altimeter settings and calculate altitude corrections.
Altimeter Setting Types
| Setting | Description | Altimeter Reads |
|---|---|---|
| QNH | Sea level pressure | Field elevation on ground |
| QFE | Field pressure | Zero on ground |
| QNE | Standard (29.92/1013) | Pressure altitude |
Quick Conversions
- 1 in Hg = 33.8639 hPa (mb)
- 1 hPa = 0.02953 in Hg
- 1 hPa change = ~27 ft altitude
- 1 in Hg change = ~1000 ft altitude
Understanding Altimeter Settings
QNH - Query Nautical Height
QNH is the pressure at mean sea level. When set, the altimeter indicates altitude above mean sea level (MSL). This is the standard setting used for en-route flight below the transition altitude.
QFE - Query Field Elevation
QFE is the actual atmospheric pressure at the airfield. When set, the altimeter reads zero on the ground at that field. Used in some countries for approach and landing.
QNE - Standard Pressure
QNE is the standard pressure setting (29.92 in Hg / 1013.25 hPa). When set, the altimeter indicates pressure altitude. Used above the transition altitude (flight levels).
Temperature Correction
In cold weather, the altimeter will read higher than actual altitude (the atmosphere is denser and "compressed"). The ICAO cold temperature correction formula is: Correction = 4% of altitude above field elevation per 10C below ISA.