Pressure Altitude Calculator
Convert field elevation and altimeter setting into pressure altitude — the entry point for every POH performance chart.
Each 0.01 inHg below standard adds 10 ft to pressure altitude. On a low-pressure day the same runway 'sits higher' in the standard atmosphere — and every performance chart starts from that number.
Formula
⚠️ For flight planning and education only — always verify against your aircraft's POH/AFM, official weather sources and certified instruments. Not for primary navigation or airworthiness decisions.
Convert field elevation and altimeter setting into pressure altitude — the entry point for every POH performance chart.
About Pressure Altitude Calculator
Pressure altitude is the quiet workhorse of flight planning: it is the altitude argument for every takeoff, climb and cruise chart in the POH, the basis of density altitude, and the height the transponder reports. This calculator applies the standard 1,000-ft-per-inch rule to your field elevation and current altimeter setting and shows the correction separately, so you can see exactly what the pressure system overhead is doing to your numbers.
How to use Pressure Altitude Calculator
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula PA = field elevation + (29.92 − altimeter setting) × 1,000 substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Pressure Altitude Calculator?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula PA = field elevation + (29.92 − altimeter setting) × 1,000 with sources cited on the page
- ✓Each 0.01 inHg below standard adds 10 ft to pressure altitude. On a low-pressure day the same runway 'sits higher' in the standard atmosphere — and every performance chart starts from that number.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
What is pressure altitude, in plain words?+
It is how high your airport 'looks' to the standard atmosphere today — the height at which the standard atmosphere has the same pressure your field actually has. Set 29.92 in the Kollsman window and the altimeter reads it directly. Performance charts use it because engines and wings care about pressure, not survey elevation.
Why does low pressure raise pressure altitude?+
When the altimeter setting is below the standard 29.92 inHg, the actual air column above the field is 'thinner' than standard. The standard atmosphere only reaches that lower pressure at a greater height, so the field maps to a higher standard-atmosphere altitude — about 1,000 ft higher per inch of mercury below standard.
When does pressure altitude equal field elevation?+
Only when the altimeter setting is exactly 29.92 inHg (1013.25 hPa). Higher settings push pressure altitude below field elevation (denser, better-performing air); lower settings push it above. The correction line in this tool shows the size and sign at a glance.
Is this the altitude my transponder squawks?+
Yes — Mode C/S transponders and ADS-B report pressure altitude from a blind encoder permanently referenced to 29.92, regardless of what you dial into the altimeter. ATC's computers then apply the local setting. That is why controllers see a consistent altitude even when pilots are flying QNH.
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