Free tool
FIDE rating calculator for chess
How it works
Enter your current rating, each opponent’s rating, your results, and the FIDE K-factor that applies to you. The calculator applies the FIDE rating rules (the 400-point cap, the score probability table, the K x games limit of 700 and whole-number rounding) and also shows the pure Elo figure. Your federation’s published rating remains the official result.
- Runs in your browser
- No email needed
- Method shown below
- 4 cited sources
FIDE uses K = 40 for new players and for juniors under 2300 until the end of the year they turn 18, K = 20 up to 2400, K = 10 once a player has reached 2400.
Every rated game on this rating list, including the ones below. If K times this number passes 700, FIDE lowers K to the largest whole number that keeps it at or under 700.
The main figure follows FIDE Rating Regulations 8.3: a gap over 400 counts as 400 for players below 2650, score probabilities come from table 8.1.2, K is capped so K times games stays at or under 700, and the total is rounded to a whole number. The pure Elo line uses the continuous formula. Your federation's published rating is the official result.
ResultUpdates as you type
Expected score
0.43 / 1
FIDE table 8.1.2 against 1450; pure Elo gives 43%
Actual score
1 / 1
New rating
1423
+23 points at K = 40 under FIDE rules. Pure Elo: +22.9
How it works
The method behind the numbers
Formula
Rating change = K x (S - Σ PD), rounded to a whole number, where PD comes from FIDE table 8.1.2 and a gap over 400 counts as 400 below 2650
The Elo system models every game as a probability. A 200-point rating gap gives the stronger player an expected score around 0.76, a 400-point gap around 0.91. Beating a much lower-rated opponent therefore earns almost nothing, while upsetting a higher-rated one moves your rating sharply.
The K-factor decides how fast ratings move. FIDE applies K = 40 to new players and to juniors until the end of the year of their 18th birthday while they stay under 2300, K = 20 once a player has an established rating below 2400, and K = 10 after a player has been 2400 or higher. Online platforms use their own systems and parameters, which is one reason online and FIDE numbers differ.
For a multi-game event, FIDE reads a score probability for each game from its table 8.1.2, after counting any gap over 400 as 400 for players rated below 2650. That below-2650 rule is the amendment effective from 1 October 2025 in the current rating regulations; for players rated 2650 and above the real difference is used. The differences between score and probability are summed, multiplied by K and rounded once to a whole number, with 0.5 rounded away from zero. If K times the games in the rating period passes 700, K drops to the largest whole number that keeps it at or under 700. The calculator does each of these steps and shows the continuous Elo result alongside. This tool estimates the change for a player who already has a FIDE rating; a first rating for an unrated player uses a different initial-rating method, which our guide to getting a FIDE rating in India walks through.
Worked example
The steps with real numbers
Illustrative figures, worked the way the tool works them. Put the same numbers into the tool above to check.
Back to the toolA worked example makes the steps concrete, with illustrative numbers rather than a real player. An established player rated 1500 beats an opponent rated 1700, a 200-point gap, at K = 20. Table 8.1.2 gives the lower-rated player a score probability of 0.24 for that gap. The rating change is K times (score minus probability), which is 20 x (1 - 0.24) = 15.2, rounded once to a whole number as 15, so the new rating is 1515. The calculator shows this result and the continuous Elo figure beside it.
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
How many points do I gain for beating a higher-rated player?
It depends on the gap and your K-factor. Against an opponent 200 points above you at K = 40, your expected score is about 0.24, so a win earns roughly 30 points. At K = 20 the same win earns about 15. The calculator shows the exact value for your numbers.
Why did my rating drop after a draw?
A draw against a lower-rated opponent scores 0.5 when your expected score was higher than 0.5, so the difference is negative. Elo treats a draw with a weaker player as underperformance, which is why strong players lose points drawing down.
Is this the same number FIDE will publish?
It applies the same rules FIDE publishes in section 8.3 of its rating regulations: the 400-point difference cap below 2650, the table 8.1.2 score probabilities, the K x games limit of 700 and whole-number rounding. FIDE rates only registered events and adds games from the whole rating period, so enter every game on the list and check ratings.fide.com for the official figure.
Why are my Lichess and Chess.com ratings so different from FIDE?
Different player pools and different rating systems. Lichess and Chess.com use Glicko-family systems with their own starting points and deviations, and the average strength of each pool differs, so the same player carries three different numbers. Compare trends, not absolute values.
What is a K-factor and why does it matter?
The K-factor sets how many rating points are at stake in a single game: the point change is K times the difference between your actual score and your expected score. A bigger K means bigger swings in both directions, win or lose. FIDE uses K = 40 for new players and for juniors rated below 2300 until the end of the year they turn 18, K = 20 once a rating is established below 2400, and K = 10 after a player reaches 2400. The same result against the same opponent moves a rating four times as far at K = 40 as it does at K = 10, so switching the K selector shows a coach the realistic range before a student’s bracket is confirmed.
Why does the number of games in the rating period matter?
FIDE caps the total points from one rating period: if your K-factor times the number of games (n) on a list passes 700, K drops to the largest whole number that keeps K times n at or under 700. Take an illustrative example of a junior at K = 40 who plays 18 rated games in the period. K times n is 40 x 18 = 720, which passes 700, so the effective K becomes floor(700 / 18) = 38, and 38 x 18 = 684 stays under the ceiling. A single nine-game event at K = 40 gives 40 x 9 = 360 and does not trigger the cap. Note that the games entered for one event and the total games on the list for the period are different inputs; the cap looks at the period total.
Start building a smarter academy
We set up your academy with you: roster import, Lichess and Chess.com connections, batches, and fee plans.