Glider ballast calculator ?
Ballast helps a glider push into wind and keep its glide in faster air. Enter the glider and either a percentage or a weight of ballast.
Result
Fill in the numbers above to see the result.
How it works
Wing loading = weight ÷ wing area. Ballast raises it, so the glider flies faster at the same glide angle: speed goes up with the square root of the weight - 21% more weight is about 10% more speed.
The glide ratio itself barely changes, but the sink rate rises with the speed, so ballast suits wind and strong lift, not light thermal days.
Add it in steps and keep it on the CG - a ballast slug in the wing joiner or a tube at the balance point is ideal.
Keep every model's numbers in one place
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