---
title: "Chess performance rating calculator"
url: "https://georgelichess.com/tools/performance-rating.md"
canonical_url: "https://georgelichess.com/tools/performance-rating"
last_updated: "2026-10-19"
type: "tool"
summary: "Turn a score against a field of opponents into a performance rating with the FIDE conversion table, from a list of games or from totals."
related: ["https://georgelichess.com/tools/rating-calculator.md", "https://georgelichess.com/tools/time-control-calculator.md"]
---

# Chess performance rating calculator

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Turn a score against a field of opponents into a performance rating with the FIDE conversion table, from a list of games or from totals.

A performance rating is the rating your results in an event would match. Take the average rating of your opponents, work out your score as a percentage, and look up the matching rating difference in the FIDE Handbook table. Add that difference to the average. This calculator does the lookup for you and also shows a quick shortcut.

## How the performance rating is computed

Rp = Ra + dp(p)

Ra is the average rating of your opponents. p is your score divided by the games played, rounded to a whole percent. dp is the rating difference the Handbook table gives for p. The clause is B02 8.1.1.

## Selected rating differences

| Score share p | Percent | Rating difference dp |
| --- | --- | --- |
| 0.50 | 50% | 0 |
| 0.60 | 60% | +72 |
| 0.75 | 75% | +193 |
| 0.90 | 90% | +366 |
| 1.00 | 100% | +800 |

The full table has a row for every whole percent and runs from -800 to +800.

## Worked examples

| Case | Score | Percent | dp | FIDE performance | Shortcut | Shortcut, rounded |
| --- | --- | --- | --- | --- | --- | --- |
| Score 6.5 of 9 against an average of 2300 | 6.5 of 9 | 72% | +166 | 2,466 | 2477.8 | 2,478 |
| Perfect score, 5 of 5, against an average of 2200 | 5 of 5 | 100% | +800 | 3,000 | 2600.0 | 2,600 |

## The shortcut

Rp = Ra + 400 x (W - L) / N

W is the number of wins, L the number of losses and N the games played. A perfect score shows it: the shortcut adds +400 to the average opponent, the most it can give, while the Handbook table adds +800. The shortcut cannot pass 400 points either side of the average, and the table runs to twice that.

## Questions people ask

**How do I calculate a performance rating?** Average the ratings of the opponents you played, divide your points by the games played to get your score, and round that to a whole percent. Look the percent up in the FIDE conversion table to get a rating difference, then add it to the average. Entering your results above does all of this.

**Why do the FIDE value and the shortcut differ?** The shortcut treats every extra win as the same number of rating points, so it is a straight line. The Handbook table is a curve that rises faster near the top and bottom of the score range. They sit close together in the middle and drift apart for very high or very low scores.

**What if I score 100 percent or 0 percent?** The table still gives an answer, because it has a row for every whole percent from 0 to 100. It is the largest difference the table holds in either direction. A perfect result in a short event says little on its own, so read it with the number of games in mind.

**Is this the same as a title norm performance?** No. A norm check starts from the same table but applies extra rules first, such as a rating floor for the lowest-rated opponents and limits on the mix of opponents. Use the title norm calculator for that. This page gives the plain performance rating for the games you enter.

## Sources

Checked against the FIDE Handbook edition dated 1 March 2024 on 2026-10-19. Conversion table: B02 8.1.1.

## Related

- [Chess rating calculator: FIDE and Elo](https://georgelichess.com/tools/rating-calculator.md)
- [Chess time control calculator](https://georgelichess.com/tools/time-control-calculator.md)