Sailing Wind Calculator

Calculate apparent wind angle and speed from true wind conditions and boat speed. Determine your velocity made good (VMG) toward the wind.

True Wind Speed

kts

True Wind Angle

Boat Speed

kts

Tab to move between fields

Apparent Wind Speed

19.7 kts

Apparent Wind Angle32.6°

Velocity Made Good4.24 kts

How to Use This Calculator

Enter the true wind speed in knots from a weather station or instrument.
Set the true wind angle in degrees — 0° is directly into the wind, 90° is a beam reach, 180° is a dead run.
Enter your current boat speed in knots.
Read Apparent Wind Speed (AWS) in knots — this is what your wind instruments and sails respond to.
Check Apparent Wind Angle (AWA) to know how to trim your sails for the actual wind your boat is experiencing.
Use Velocity Made Good (VMG) in knots to evaluate how efficiently you are making progress toward an upwind or downwind mark.

How the result changes with True Wind Speed

True Wind Speed: The actual wind speed measured relative to the ground or water surface, typically from weather reports or an anemometer.
True Wind Angle: Angle between the boat's heading and the true wind direction. 0° = head-to-wind, 90° = beam reach, 180° = dead downwind.
Boat Speed: Current speed of the boat through the water, measured by a knotmeter or GPS.

Apparent Wind Speed: The wind speed as felt on the boat, combining true wind with the boat's own motion.
Apparent Wind Angle: The angle of the wind relative to the bow as experienced on the moving boat.
Velocity Made Good: The component of boat speed directly toward (or away from) the wind. Positive = upwind progress, negative = downwind.

Identify Input Parameters
True Wind Speed = 15, True Wind Angle = 45, Boat Speed = 6 = 3 input(s) provided
Calculate Apparent Wind Speed
Apparent Wind Speed
19.7 = 19.7
Calculate Apparent Wind Angle
Apparent Wind Angle = Math
32.6 = 32.6
Calculate Velocity Made Good
Velocity Made Good
4.24 = 4.24