Free tool
Performance rating calculator (linear estimate)
How it works
Enter the rating of every opponent you faced and your total score. The result is a linear estimate: the average opposition rating plus 800 times your score percentage minus 400, so a 50% score performs exactly at the average of the field. FIDE publishes its own score-to-rating-difference table, so a FIDE figure can differ, most of all at very high or very low scores.
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- Method shown below
- 4 cited sources
This is the linear estimate. FIDE's own table converts a percentage score into a rating difference and gives different results at high and low scores: against a field averaging 1500, a perfect score reads 1900 here and 2300 on the FIDE table. The result describes this event only. It is not a published rating, and one figure does not establish a title norm.
ResultUpdates as you type
Average opposition
1490
Score percentage
75%
Performance rating
1690
Linear method: average + 800 x score% - 400
How it works
The method behind the numbers
Formula
Rp = average opposition + 800 x (score / games) - 400
Performance rating answers a different question than your rating change: not "what is my new rating" but "what rating did I play like in this event". A 75% score against 1500-average opposition is a roughly 1700 performance on the linear formula, regardless of what your own rating was coming in.
This page uses the linear method on purpose. FIDE’s Rating Regulations (effective 1 March 2024) publish a table that converts a percentage score into a rating difference, and it matches the linear method closely in the middle of the range and diverges at the extremes. For a field averaging 1500, the table below compares the two. The linear result is the displayed formula worked out. The FIDE column is average opposition plus the rating difference from table 8.1.1, which the regulations show notionally as 800 for a perfect score.
A performance rating is an estimate for one event, not a published rating. To work out how a rating changes after an event, use the FIDE rating calculator, and to keep a dated record of a student’s ratings across events, use the rating tracker. For title norms, the FIDE Title Regulations set performance thresholds (a GM norm needs a performance of at least 2600 against opponents averaging at least 2380, an IM norm 2450 against at least 2230) alongside other requirements. This page is not a norm eligibility tool, so read the current regulations before planning one.
| Score | Linear formula | Linear result | FIDE table difference | FIDE table result |
|---|---|---|---|---|
| 50% | 1500 + 800 x 0.50 - 400 | 1500 | 0 | 1500 |
| 75% | 1500 + 800 x 0.75 - 400 | 1700 | +193 | 1693 |
| 100% | 1500 + 800 x 1.00 - 400 | 1900 | +800 (notional) | 2300 |
The same job inside ChessCore
Chess student progress tracking
Chess student progress tracking is following each student across a season on recorded signals: attendance, game results, ratings and coach notes, and turning those into a report. ChessCore keeps all four in one record. AI-written report text is approved by a coach, and automatic monthly emails, when an academy switches them on, carry the records with no AI text.
See progress tracking
Questions
Frequently asked questions
What does a performance rating actually mean?
It estimates the rating level that matches your score against the opposition you actually faced, using the method shown. On the linear method, 6/9 against 1600-average opposition gives 1600 + 800 x 0.667 - 400, about 1733. It measures one event, not your overall strength, and it is a different calculation from asking which single rating would make your score exactly expected against opponents of different strengths.
What happens at a perfect score?
The linear formula stays finite: it gives the average opposition plus 400 at 100% and minus 400 at 0%. A formulation that asks which rating makes the score exactly expected has no finite answer at a perfect score, and FIDE’s table calls the difference indeterminate and shows it notionally as 800. These answer different questions, so a perfect score against a 1500 field reads 1900 here and 2300 on the FIDE table.
Does one performance rating earn a title norm?
No. A single figure does not establish a norm. The FIDE Title Regulations (effective 1 January 2024) set performance thresholds against minimum opponent averages, together with other requirements, and they use the regulations’ own conversion table. Check the current regulations on the FIDE Handbook before planning a norm attempt.
Why does another calculator give a different number?
Calculators differ in method. Some use the linear formula shown here, some convert the score with FIDE’s table and some solve for the rating that makes the expected score match. Check which method a page uses and compare like with like.
How is this different from the FIDE rating calculator?
The rating calculator estimates how your published rating changes after games, using K-factors and expected scores. This page estimates the level you performed at in one event from your score and your opponents, and it does not change a rating.
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