About Courtkit
A small, independent set of free tools for people who play tennis.
Courtkit exists because the simple questions in tennis are oddly hard to get a straight answer to. What size racket does a seven-year-old need? What does a grip size of 3 mean? How do you run a round robin for nine people on two courts? Each page here answers one of those and nothing else.
How the tools are made
Everything runs in your browser. There is no account, nothing to download, and the tools keep working if your signal drops at the court. Measurements and rules follow the standard published figures for the sport, and where brands or federations differ the page says so.
A note on advice
The calculators give sensible starting points, not professional fitting or medical advice. If a racket, grip or string setup hurts, stop and speak to a coach or a physio.
Cost
The tools are free. The site may show adverts to cover its running costs; the privacy page explains what that means for you.