Ground Speed Wind
Calculator
Results
- Ground speed (knots)
- 122.5
- Headwind component (knots)
- 12.5
- Crosswind component (knots)
- -21.650635
Aviation and marine results
| Ground speed (knots) | 122.5 |
| Headwind component (knots) | 12.5 |
| Crosswind component (knots) | -21.650635 |
formula-map diagram
- Ground speed (knots)
- 122.5
- Headwind component (knots)
- 12.5
- Crosswind component (knots)
- -21.650635
Aviation and marine relationship
Formula
GS = TAS − V × cos(wind − course)= 122.5
Note
This is a simplified model: it applies a standard navigation, performance or seamanship formula to the numbers you entered. True airspeed and density altitude use the ISA troposphere model for dry air and ignore humidity, compressibility and instrument or position error, so they are not a substitute for your aircraft's flight manual or an air data computer. Wind, climb, descent and fuel figures assume a steady wind and a constant speed and fuel flow for the whole leg; they ignore manoeuvring, holding, taxi and start-up fuel, terrain, turbulence and air traffic control routing. Takeoff distance scales an entered sea level figure by a rule-of-thumb percentage per 1000 ft of density altitude and is not a certified performance chart. Weight and balance results depend entirely on the arms and weights you enter and must be checked against the approved loading envelope. Hull speed is the classic 1.34 × √LWL displacement estimate, boat fuel burn is a horsepower-based approximation, anchor scope is a rule of thumb, and the rule of twelfths is a linear approximation of a sinusoidal tide that does not hold in all locations. Always use official charts, tide tables, the aircraft or vessel manuals and current weather, and treat these numbers as planning estimates only.
More in Aviation and marine
See all →Frequently asked questions
What does this calculator actually compute?+
It combines your true airspeed, heading, and the wind's speed and direction to determine your groundspeed — how fast you are actually moving over the earth's surface. This is the vector sum of your airspeed vector and the wind vector.
Why can groundspeed be higher or lower than true airspeed?+
A tailwind component adds to your airspeed, pushing groundspeed higher, while a headwind component subtracts from it, lowering groundspeed. A pure crosswind has little effect on groundspeed but pushes the aircraft off its intended track instead.
How does wind direction interact with heading in the calculation?+
The calculator breaks the wind into two components relative to your heading: a headwind/tailwind component along your direction of travel and a crosswind component perpendicular to it. Only the along-track component directly changes groundspeed; the crosswind component affects drift instead.
What's a common misconception about wind and flight time?+
Pilots sometimes assume a headwind and tailwind of equal strength cancel out over a round trip, but they don't — the time lost fighting the headwind is always greater than the time saved with the tailwind, because you spend more total time at the slower groundspeed.
What if the wind is reported at a different altitude than my flight level?+
Wind speed and direction change significantly with altitude, so using surface wind for an enroute calculation at cruise altitude will give inaccurate results. Always use the forecast or reported winds aloft for the altitude you're actually flying at.