Pressure Altitude
Calculator
Results
- Pressure altitude (m)
- 609.0422
- Pressure altitude (ft)
- 1,998.169947
- Pressure correction (m)
- 109.0422
Weather results
| Pressure altitude (m) | 609.0422 |
| Pressure altitude (ft) | 1,998.169947 |
| Pressure correction (m) | 109.0422 |
formula-map diagram
- Pressure altitude (m)
- 609.0422
- Pressure altitude (ft)
- 1,998.169947
- Pressure correction (m)
- 109.0422
Weather relationship
Formula
PA = field elevation + (1013.25 − QNH) × 8.2296 m/hPa (27 ft per hPa, ISA)= 609.0422
Note
This is a simplified model: it applies the published standard formula to the numbers you entered and ignores local terrain, radiation, precipitation type and instrument error. Wind chill is the 2001 NWS/Environment Canada regression, valid at or below 10 °C with wind at or above 4.8 km/h; the heat index is the Rothfusz regression, reliable above about 27 °C; dew point uses the Magnus approximation (a = 17.27, b = 237.7 °C) over liquid water; wet bulb uses Stull's approximation at standard sea-level pressure; pressure and density altitude assume the International Standard Atmosphere and dry air. Do not use these results for aviation, structural or safety decisions without an official forecast or a qualified professional.
More in Weather and climate
See all →Frequently asked questions
What is pressure altitude and why isn't it the same as elevation?+
Pressure altitude is the altitude indicated by an altimeter set to the standard sea-level pressure reference of 29.92 inHg (1013.25 hPa), regardless of the actual local pressure that day. It only matches true elevation when the local barometric pressure happens to equal that standard value.
How is pressure altitude calculated from field elevation and local pressure?+
Pressure altitude equals field elevation plus 1,000 feet for every 1 inHg that the local altimeter setting is below 29.92 (or minus 1,000 feet for every 1 inHg above it), reflecting how atmospheric pressure changes with altitude near sea level.
Why do pilots need pressure altitude instead of just using true elevation?+
Pressure altitude is required to correctly compute aircraft and engine performance figures (like density altitude, true airspeed corrections, and some takeoff/landing distance charts), since those depend on how the atmosphere actually behaves at that pressure level, not on the ground's literal height above sea level.
Why does pressure altitude change even if an airport's elevation never does?+
Because local barometric pressure fluctuates with weather systems day to day, the same fixed-elevation airport will show a different pressure altitude on a high-pressure day than on a low-pressure day, since pressure altitude reflects that day's actual atmospheric conditions relative to the standard reference.
What's the relationship between pressure altitude and density altitude?+
Pressure altitude is the input adjusted only for pressure; density altitude takes pressure altitude and further corrects it for the actual air temperature, since hot air is less dense than the standard atmosphere predicts. Density altitude is always the more complete, and usually higher, figure on a warm day.