Use this calculator for flight-planning study or a first-pass cross-check when all inputs describe the same aircraft, atmospheric condition, and phase of flight.

Indicated altitude (ft)

Indicated altitude above the station or datum.

ISA temperature (°C)

ISA standard temperature at this altitude.

OAT (°C)

Actual outside air temperature.

Compute the cold-weather altimeter correction so the altimeter reads true altitude in colder-than-standard air. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Corrected altitude (ft)

Altitude to set on the altimeter after correction.

Correction (ft)

Signed altitude correction applied; positive when cold.

• Do not use a generic calculator in place of the current aircraft flight manual, approved performance data, operating limitations, NOTAMs, weather, or regulations. Real performance changes with configuration, runway condition, altitude, temperature, wind, loading, and technique.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check the result against the aircraft flight manual or approved planning system, then apply the required safety margins. Keep signed wind, heading, altitude, speed, and fuel conventions explicit.

• Corrected Altitude Calculator

  Compute what an altimeter would indicate for a known true altitude under non-standard temperature — the inverse of the cold-weather altitude correction.

• Cold Temperature Correction Calculator

  Estimate the altitude correction for cold temperatures against the ISA atmosphere.

• Density Altitude ISA Correction Calculator

  Estimate density altitude from pressure altitude and outside air temperature using the ISA lapse rate.