True Airspeed (TAS) Calculator
Convert indicated airspeed to true airspeed based on altitude and temperature.
Rule of Thumb
TAS increases approximately 2% per 1,000 feet of altitude above sea level at standard temperature.
Temperature also affects TAS: warmer = faster TAS, colder = slower TAS for the same IAS.
Airspeed Types
- IAS: What the airspeed indicator shows
- CAS: IAS corrected for instrument/position error
- TAS: Actual speed through the air mass
- GS: Speed over the ground (TAS +/- wind)
Understanding True Airspeed
Why TAS Differs from IAS
The airspeed indicator measures dynamic pressure, which decreases as air density decreases. At higher altitudes, the thinner air means you're actually moving faster through the air than indicated.
When to Use TAS
- Flight planning and navigation
- Calculating ground speed with wind
- Time and distance calculations
- Filing flight plans
When to Use IAS
- Aircraft operating limitations (Vne, Va, Vfe, etc.)
- Stall speeds
- Pattern and approach speeds