Free tools

Free tennis trading tools

Quick calculators for tennis prediction markets. They run in your browser, they work on your phone, and you don't need an account.

• Free tool

  Tennis odds converter

  Turn a price in cents into a probability and every common odds format.

  Free, no sign-up
• Free tool

  Tennis trading profit calculator

  See your shares, profit or loss and break-even price before you trade.

  Free, no sign-up
• Free tool

  Tennis win-chance calculator

  Type in the score and get each player's estimated chance of winning the match.

  Free, no sign-up

Learn the basicsWhat the numbers mean.

• Learn

  How tennis prices work: why 62¢ means a 62% chance

  Price equals probability. Here's why, and how it moves with every point.

  7 min read
• Start here

  Tennis trading on prediction markets: the complete beginner's guide

  What it is, how prices work, buying and selling mid-match, the risks, and how to practise.

  9 min read

Demo only. 77 Tennis uses demo money with no cash value. Nothing here is financial or betting advice. Prices come from Polymarket's public tennis markets, and I'm not affiliated with Polymarket. Prediction markets aren't legal everywhere, so check the rules where you live. If trading stops being fun, stop.