Free chess calculator
Expected points over a run
Set your rating gap to the field and how many games you'll play, and see the score you should expect — plus the range it can realistically swing across.
How you rate against the average opponent in the event.
A weekend Swiss is usually 5–9 rounds.
The single number hides the spread: even as a clear favourite, a short event can swing a point or more either way. Use the range, not the point estimate, to set expectations — and remember one bad round is noise, not a verdict.
How the number is built
The Elo model converts a rating gap into a single win-expectancy number, E, between 0 and 1 — the fraction of a point one side is expected to score per game. Multiply E by the number of games and you get expected points over the whole run; the same E, treated as a per-game win probability, also gives you the spread: a run of independent games has a binomial-style variance of N × E × (1 − E), so the standard deviation is just the square root of that.
A worked example
A 200-point favourite has E ≈ 0.76 per game — call it a 76% expected score. Over a 10-game match that's 7.6 points on average, but the spread (≈ √(10 × 0.76 × 0.24) ≈ 1.35) means anywhere from about 6.2 to 9.0 points is a completely ordinary result, not an upset or a slump. That's the whole reason the calculator shows a band instead of a single confident-looking number: a 200-point favourite scoring 6 wins and 4 losses across 10 games is well within normal variance, not evidence the rating gap was wrong.
Straight answers
Why show a range instead of one number?
Because a short event is noisy. Even a clear favourite can finish a point above or below their expected score just from variance. The range (about one standard deviation) is a more honest expectation than the single point.
Does it account for draws?
The expected score does. The spread uses a simple win/loss variance model, so it slightly overstates the swing when draws are common — treat it as a rough band, not a precise interval.
Related tools
Your win/draw/loss odds against any opponent, and exactly what a win, draw or loss does to your rating.
Turn a rating gap into a probability and plain odds — and see why the curve is an S, not a line.
Turn a tournament score into the rating you actually played at — the number a good event is really worth.
Educational chess content. Rating math uses the standard Elo model; results are estimates and vary by federation, pool and time control.