Ground Speed Calculator

Calculate your ground speed by entering your airspeed and wind speed

Input Parameters

0° = Headwind, 180° = Tailwind, 90° = Crosswind from right, 270° = Crosswind from left

Calculation Results

Calculation Results

Ground Speed: -- knots

True Course: -- degrees

Calculation Formula

Ground Speed = √(Airspeed² + Wind Speed² + 2 × Airspeed × Wind Speed × cos(θ))

Where:
Airspeed = Aircraft's speed through the air
Wind Speed = Speed of wind relative to the ground
θ = Angle between airspeed and wind direction (0° = headwind, 180° = tailwind)

Ground Speed Calculator Usage Guide

Learn how to use the Ground Speed Calculator and understand its working principles

How to Use the Calculator

  1. Enter your aircraft's airspeed in knots (the speed your aircraft is traveling through the air).
  2. Enter the wind speed in knots (the speed of the wind).
  3. Enter the wind direction in degrees (0° = directly headwind, 180° = directly tailwind, 90° = crosswind from right, 270° = crosswind from left).
  4. Click the "Calculate" button to compute your ground speed and true course.
  5. Click "Reset" to clear all inputs and start over.

Understanding Ground Speed

Ground speed is the speed at which an aircraft travels over the ground. It differs from airspeed (speed through the air) because of wind effects:

  • Headwind (0° wind direction): Increases ground speed. Ground Speed = Airspeed + Wind Speed
  • Tailwind (180° wind direction): Decreases ground speed. Ground Speed = Airspeed - Wind Speed
  • Crosswind (90° or 270° wind direction): Creates a vector component that affects both ground speed and true course.

Principle of Calculation

This calculator uses vector addition to calculate ground speed. The formula accounts for both the magnitude and direction of airspeed and wind speed:

Ground Speed = √(Airspeed² + Wind Speed² + 2 × Airspeed × Wind Speed × cos(θ))

Where θ is the angle between airspeed and wind direction. This formula properly accounts for all three possible wind components (headwind, tailwind, and crosswind) in a single calculation.