Performance Rating Calculator

What a performance rating says

A performance rating, often written TPR or Rp, is the rating at which a player's results in an event would have been exactly as expected. If your performance is above your rating, you played better than your rating predicts and your rating will rise; below it, it will fall. Performance ratings are also how FIDE decides whether a result is good enough for a title norm.

The FIDE method

FIDE calculates performance as Rp = Ra + dp. Ra is the average rating of the opponents, rounded to the nearest whole number. dp is a rating difference read from a table using the percentage score p, rounded to two decimals. The table is symmetrical: 50% gives 0, 60% gives +72, 64% gives +102, 75% gives +193, 90% gives +366, 99% gives +677 and 100% gives +800. Scoring 4½ from 7, 64%, against opponents averaging 2010 gives 2010 + 102 = 2112. Because the table is based on a normal distribution, its values differ slightly from the logistic Elo curve, and the table's cap at ±800 means a perfect score cannot give an unlimited performance.

The linear and exact methods

Two simpler and two more exact methods are widely quoted. The linear method, often used for quick estimates, is Ra + 400 × (wins − losses) ÷ games. For the same event, three wins, three draws and a loss, it gives 2010 + 400 × 2 ÷ 7 = 2124. The exact method finds the single rating at which the sum of expected scores against each individual opponent equals the actual score; it is the true "no rating change" figure, here 2116. The three methods agree to within a few points for most results and diverge for extreme scores. A common misconception is that a performance rating is a prediction of your future strength; it measures one event, and a seven-game sample has a standard error of well over 100 points.

Why averages hide things

FIDE's method uses only the average opponent rating, so a field of one 2400 and one 1600 counts the same as two 2000s. That is a practical simplification; the exact method accounts for each opponent separately and gives a more faithful figure when the field is very uneven. Unplayed games and byes are left out of performance calculations, and in norm events the regulations allow the lowest-rated opponents to be raised to a rating floor.

How to use it

1. Enter each opponent's rating and your result, round by round.
2. Leave unplayed games and byes empty.
3. Read the FIDE performance from the dp table, with the average opponent rating and percentage.
4. Compare with the linear and exact methods, especially for very high or low scores.