Surface Elo

Type two player names into the boxes below (start typing and pick from the suggestions), choose a surface — Hard, Clay, or Grass — and press Calculate true odds.

You'll get each player's estimated chance of winning, the "fair" decimal odds and moneyline that chance implies, and their past head-to-head results if they've played before.

If you've got odds from a bookmaker for the same match, pop them into the two boxes at the bottom of the results to see whether the bookmaker's price looks generous or stingy compared to this model.

The leaderboard further down shows the current top players on each surface, based on results through 2026-09-12.

Download the current-year file (or any updated file) from tennis-data.co.uk's "All  data" page and drop it in here. Same column layout as the original ATP files works automatically (Date / Winner / Loser / Surface / Comment). New matches merge in and duplicates are skipped automatically — ratings recalculate instantly in your browser. Nothing is uploaded anywhere; it's all processed locally on this page. Once you've merged new data, use your browser's Save Page As (Ctrl/Cmd+S) and choose "Webpage, HTML only" to save it as a new file with the update baked in — otherwise it's only good for this browser session and reverts to the built-in data on reopen.