Work out glide ratio instantly with clear inputs, formula shown and shareable results.
Glide ratio is horizontal distance divided by height lost in the same units, so it equals the aerodynamic lift-to-drag ratio when flown at the correct speed. A 4 nautical mile glide from 2,500 ft is about 9.7:1. Weight changes the best glide speed but not the ratio itself.
Glide ratio
L/D = horizontal distance / height lost (same units); angle = atan(1 / (L/D))
Aviation results are planning estimates only. Always verify take-off, landing, fuel, weight and balance figures against the certified Aircraft Flight Manual, current performance charts and applicable aviation regulations before flight.
A heavier aircraft glides at the same angle but at a higher speed and higher sink rate, so it covers the same distance in less time.
Around 9:1 for a light single, 15-18:1 for a modern jet transport in clean glide, and 40:1 or more for a competition glider.