Chess Tournament Performance Rating Calculator
Calculate your chess tournament performance rating from your score and opponents' average rating. Use this after any rated tournament to estimate the Elo rating you performed at.
About this calculator
Performance rating estimates the Elo rating a player demonstrated during a tournament. The formula first converts your score percentage into a rating difference (Dp) using the FIDE lookup table, approximated as: Dp = 400 × log₁₀(percentage / (1 − percentage)). This Dp is then added to your average opponent rating: Performance Rating = avgOpponentRating + Dp. If you scored 100% the Dp is capped at +800, and 0% is capped at −800. For example, scoring 70% against 1500-rated opponents yields Dp = 400 × log₁₀(0.7 / 0.3) ≈ 147, giving a performance rating of 1647. This metric is widely used by FIDE and national federations to award titles and norms.
How to use
Suppose you played 9 games in a tournament, scored 6.5 points, and your average opponent rating was 1800. Step 1 — compute percentage: 6.5 / 9 ≈ 0.722. Step 2 — compute Dp: 400 × log₁₀(0.722 / (1 − 0.722)) = 400 × log₁₀(0.722 / 0.278) = 400 × log₁₀(2.597) ≈ 400 × 0.4145 ≈ 166. Step 3 — add to average opponent rating: 1800 + 166 = 1966. Your tournament performance rating is approximately 1966.
Frequently asked questions
What is chess tournament performance rating and how is it different from my Elo rating?
Performance rating measures the Elo strength you demonstrated in a specific tournament, based on your score and the ratings of your opponents. Unlike your official Elo rating, which is a long-term running average updated after each rated event, performance rating is a snapshot of a single event. A strong performance rating in a norm tournament can qualify you for FIDE titles such as FM, IM, or GM. It does not replace your official rating but is used alongside it for title purposes.
How does FIDE calculate the Dp rating difference from a percentage score?
FIDE uses a published table that maps score percentage to a rating point difference (Dp). The mathematical approximation is Dp = 400 × log₁₀(p / (1 − p)), where p is your score as a decimal. This is derived from the logistic Elo probability function. For perfect scores (100%) FIDE caps Dp at +800, and for zero scores at −800, to prevent infinite values. This calculator uses the same approximation and caps.
When should I use a performance rating calculator to check my tournament results?
Use this calculator immediately after any rated chess tournament to gauge how well you played relative to the field. It is especially valuable when you are chasing a FIDE title norm, since norms require a minimum performance rating against a sufficiently strong and international field. Players also use it to compare their performance across different events and to set realistic rating goals. Coaches use it to track student progress tournament by tournament.