Free tool
Elo Win Probability Calculator
Enter two Elo ratings — from our own Elo Rankings or anywhere else — and see the win probability the gap implies.
Embed this calculator on your own site
Free to use anywhere — a small "Powered by ServedBets" link stays on the embed. Paste this where you want it to appear:
How this is calculated
The standard Elo win-probability formula on a 400-point scale — the same one our own surface-specific Elo model uses:
P(A wins) = 1 / (1 + 10^(−(EloA − EloB) / 400))
A 100-point gap works out to roughly 64%, 200 points to roughly 76%, and 300 points to roughly 85% for the higher-rated player. This calculator doesn't know anything about tennis specifically — it's the general Elo formula, applied to whatever two ratings you enter.
Pull real, current numbers from the Elo Rankings page, which is filterable by surface — remember to compare hard-court Elo to hard-court Elo, not overall to overall, for a hard-court match.
See today's picks live
Every model output, tracked and discussed in real time — join the 3,000+ member community where it all happens.