Calculators

Free, no sign-up, and they show their working. Every default is visible and editable, and every one of them says what it assumes rather than handing you a confident number and leaving you to find out.

The reasoning behind them

Each of these has a written guide behind it explaining where the numbers come from and what they assume — part of a set on the practical side of running a gliding club.

Read the guides →

More coming, slowly and on purpose

We would rather have three calculators that are right than a dozen that look impressive. If there's a number you work out by hand every season and wish you didn't have to, tell us what it is.