Over ground
glide ratio = distance over ground ÷ height lost
9 km flown for 1,000 m of height is 9 : 1. It's what you see from a map or GPS track, and it includes the effect of wind and of rising or sinking air.
Paragliding Glide Ratio Calculator
Work out your glide ratio from distance and height lost, or from speed and sink rate. See what wind does to it, and how far your height can take you.
- Glide ratio over ground
- 9.0 : 1
- Glide angle
- 6.3°
- Height lost
- 111 m/km
How far can I glide?
9.0 km (5.6 mi)
In a straight line, at the glide ratio over ground above. Real air, terrain, and the height you need for a landing setup all take some of this away, so don't rely on it alone in the air.
How glide ratio is calculated
Through the air
glide ratio = airspeed ÷ sink rate
Use the same units for both. 38 km/h is 10.6 m/s, and 10.6 ÷ 1.1 m/s of sink is 9.6 : 1. This is the number on a glider's spec sheet, and wind doesn't change it.
What wind does
glide over ground = (airspeed ± wind) ÷ sink rate
The same 9.6 : 1 glider makes 5.8 : 1 over ground into a 15 km/h headwind and 13.4 : 1 with a 15 km/h tailwind. That's why you speed up into a headwind and slow down with a tailwind.
What sinking air does
sink rate = glider sink ± air movement
A vario reads your total sink, so it includes moving air. In 1 m/s of sinking air, that glider's sink becomes 2.1 m/s and its glide drops to about 5 : 1.
Check a real glide: open your flight in the IGC viewer for its altitudes and distance, and watch it in 3D.
Frequently asked questions
How do I calculate glide ratio?
Divide the distance you flew by the height you lost, in the same units. Or divide your airspeed by your sink rate, in the same units. 10 km for 1,000 m of height is 10,000 ÷ 1,000, a glide ratio of 10 : 1.
What is the difference between glide over ground and glide through the air?
Glide through the air is how far the glider moves through the air mass per metre of height lost, and it's a property of the wing and its speed. Glide over ground is what you actually cover across the landscape, so it changes with wind. With no wind and no vertical air movement, the two are the same.
What is a good glide ratio for a paraglider?
Most paragliders reach about 8 to 12 in still air, with the higher figures for performance wings. Your glide in real conditions is often lower, and accelerating costs glide as well.
Can I use the speed from my GPS or vario?
Yes, but know what you get. GPS speed is ground speed, so with wind left at zero, the result is glide over ground. To get glide through the air, enter your airspeed. The average of your GPS speed flown in opposite directions along the same line is a good estimate of it.
Does wing loading change the glide ratio?
Hardly. A heavier pilot flies the same glide ratio at a higher speed. It matters in a headwind, because the extra speed gives you more ground speed.
Does this calculator handle crosswind?
No. It takes wind straight on the nose or straight behind you. A crosswind also changes your glide over ground, because you have to crab into it, so treat the result as a guide on those days.