FLIGHT TOOLS / CALCULATORS

Indicated Airspeed Calculator

Accurate inputs. Clear results.

Altitude unitsIndicated altitude

Pressure unitsAltimeter setting

Temperature unitsStatic outside air temperature

TAS unitsTrue airspeed

Aircraft correction: CAS minus IAS (kt, optional)

How to use & limitations

TAS and atmospheric data determine CAS, not instrument-specific IAS. Enter CAS − IAS from your aircraft calibration data to estimate IAS. A +2 kt correction means IAS = CAS − 2 kt. Leaving it blank shows CAS only. Subsonic dry-air model; pressure altitude uses the 1,000 ft/inHg approximation. Density altitude inverts ISA. Validated model altitude −1 to 20 km; indicated altitude −2,000 to 60,000 ft; temperature −100 to 60 °C; QNH 25–35 inHg.