Aviation Training Experts

Aviation Training Experts™

ISA Deviation Calculator

Calculate ISA deviation using elevation and outside air temperature. This tool helps pilots determine how current conditions differ from standard atmosphere values.

Calculate ISA Deviation

How It Works

ISA deviation compares actual temperature to standard atmosphere temperature at a given altitude.

ISA Deviation = OAT - ISA Temperature
ISA Temperature ≈ 15 - 2 × (Elevation / 1000)