About this tool
The Glide Distance Calculator estimates how far an aircraft can travel in a power-off glide from a given height above the ground, using its glide ratio (lift-to-drag, L/D). Choose distance mode to get the range from a height and ratio, or ratio mode to back out the glide ratio from a known height and distance. It runs locally in your browser.
In distance mode, glide distance in nautical miles = height (ft) × glide ratio ÷ 6076.12, where 6076.12 is the number of feet in one nautical mile. The result is also shown in statute miles and kilometres. In ratio mode the glide ratio is horizontal distance ÷ height lost in the same units, so it converts your nautical-mile distance back to feet before dividing.
A glide ratio of 9:1, for instance, means the aircraft moves 9 units forward for every 1 unit of descent, so from 5000 ft it covers about 7.4 nm in still air. Real gliding range is reduced by wind, weight, configuration and pilot technique, so use this as a first estimate and fly your aircraft's published best-glide figures.