Calculate glide ratio from horizontal distance and altitude lost. This free aviation calculator helps pilots understand glide performance for training and emergency planning.
Enter horizontal distance and altitude lost to estimate glide ratio. Choose the distance unit that matches your known distance.
This calculator converts nautical miles or statute miles into feet before calculating glide ratio.
Glide ratio is the relationship between horizontal distance traveled and altitude lost during a glide. It is usually expressed as a ratio such as 9:1, 10:1, or 12:1.
A higher glide ratio means the aircraft can travel farther horizontally for each unit of altitude lost, assuming still-air conditions and proper glide technique.
It means the aircraft may travel about 9 units horizontally for every 1 unit of altitude lost in still air.
For practical glide planning, altitude above ground level is usually the more useful value because it reflects usable height above the terrain.
True aerodynamic glide ratio is based on air movement through the air mass, but ground distance achieved can be reduced by headwind or increased by tailwind.
No. This calculator is a planning aid. Actual glide performance depends on aircraft type, configuration, weight, speed control, wind, and pilot technique.