Speed & Distance per Minute
Enter a speed in knots, mph, feet/sec, meters/sec, or km/h. All conversions update instantly.
Barometer Conversion
Convert altimeter/barometric pressure between hectopascals (hPa / mb) and inches of mercury.
Density Altitude
Enter pressure altitude and outside air temperature. The calculator uses standard-atmosphere pressure with actual temperature to determine air density and the equivalent ISA density altitude.
For flight planning/performance, use the approved AFM/POH and current weather data. Humidity is not included.
True Airspeed
Estimate TAS from calibrated airspeed (or IAS as an approximation), pressure altitude, and OAT using air-density ratio.
Best accuracy requires CAS. If you enter IAS, the result does not correct for instrument/position error. This density-ratio method is a practical subsonic estimate and is not a replacement for an aircraft AFM/FMS.
Wind Chill
Enter air temperature and wind speed. Uses the standard U.S. National Weather Service wind-chill formula.
The standard wind-chill formula applies at 50 °F (10 °C) or colder with wind speeds of at least 3 mph.
Heat Index
Enter air temperature and relative humidity. Uses the NOAA/NWS heat-index equation.
Heat index is intended for warm, humid conditions in shade/light wind. Direct sun can make conditions feel hotter.