Chess ELO Calculator
See how many rating points you gain or lose. Enter your rating, each opponent's rating and the result, pick your K-factor, and the calculator applies FIDE's rules: the expected-score table, the 400-point rule and the rounding.
Not sure what your rating is yet? Find your level with the chess ELO test.
Your games
Rating change
+5
New rating 1655 (from 1650)
- Score
- 1.5 / 3
- Expected
- 1.27
- K used
- 20
- Performance
- 1707
20 × (1.5 − 1.27) = 20 × +0.23 = +4.6, rounded to +5. Performance equals the average opponent rating (1707), because a 50% score adds nothing in FIDE's table 8.1.1.
Game by game
| # | Opponent | Result | Difference | Expected | Change |
|---|---|---|---|---|---|
| 1 | 1720 | Win | −70 | 0.40 | +12 |
| 2 | 1590 | Draw | +60 | 0.58 | −1.6 |
| 3 | 1810 | Loss | −160 | 0.29 | −5.8 |
Difference is your rating minus the opponent's. Expected is your expected score from that game. Changes are shown before rounding; FIDE rounds only the total, to the nearest whole number with 0.5 rounded away from zero (8.3.4).
How FIDE Calculates a Rating Change
The Elo system, named after the physicist Arpad Elo and adopted by FIDE in 1970, compares the score you made with the score your rating predicted. FIDE's regulations (section 8.3) do it in four steps:
- Find the rating difference with each opponent. A gap of more than 400 points counts as 400.
- Look up your expected score for that difference in FIDE's table: 0.50 for an equal opponent, 0.64 when you are 100 points higher, 0.36 when you are 100 points lower.
- For each game, subtract the expected score from what you actually scored: 1, 0.5 or 0.
- Add those up over the rating period, which is one calendar month of rated games, multiply by your K-factor, and round to the nearest whole number. That is your rating change.
Worked example
You are rated 1650 with K = 20 and play someone rated 1750. You are 100 points lower, so FIDE expects 0.36 from you.
- Win: 20 × (1 − 0.36) = +12.8, rounded to +13
- Draw: 20 × (0.5 − 0.36) = +2.8, rounded to +3
- Loss: 20 × (0 − 0.36) = −7.2, rounded to −7
Your opponent's rating moves by the same amount the other way when you both have the same K.
Expected Score by Rating Difference
Most explanations give the Elo formula, E = 1 / (1 + 10(Rb − Ra) / 400). FIDE does not use it directly: its regulations (table 8.1.2) list the expected score for each band of rating difference, rounded to two decimals and based on the normal distribution. Inside the 400-point cap the two never differ by more than 0.015, as the table shows. The calculator uses FIDE's table by default and lets you switch to the formula.
| Difference | FIDE table | Elo formula | Favourite wins | Underdog wins |
|---|---|---|---|---|
| 0 | 0.50 | 0.500 | +10 | +10 |
| 25 | 0.53 | 0.536 | +9.4 | +10.6 |
| 50 | 0.57 | 0.571 | +8.6 | +11.4 |
| 75 | 0.60 | 0.606 | +8 | +12 |
| 100 | 0.64 | 0.640 | +7.2 | +12.8 |
| 150 | 0.70 | 0.703 | +6 | +14 |
| 200 | 0.76 | 0.760 | +4.8 | +15.2 |
| 250 | 0.81 | 0.808 | +3.8 | +16.2 |
| 300 | 0.85 | 0.849 | +3 | +17 |
| 350 | 0.89 | 0.882 | +2.2 | +17.8 |
| 400+ | 0.92 | 0.909 | +1.6 | +18.4 |
Expected score is for the higher-rated player; the lower-rated player's is 1 minus it. The last two columns are the points the winner gains at K = 20 before rounding. After a draw the favourite loses, and the underdog gains, half the difference between those two columns.
Which K-Factor Applies to You
K sets how far one tournament can move your rating. FIDE's rule 8.3.3 gives three values, and the same ones apply to the rapid and blitz lists:
| K | Who it applies to |
|---|---|
| 40 | New players, until they have completed events with at least 30 games. Also all players until the end of the year of their 18th birthday, as long as their rating stays under 2300. |
| 20 | Players whose rating has stayed under 2400. |
| 10 | Players whose published rating has reached 2400. It stays at 10 even if the rating later drops below 2400. |
One more rule limits busy months: if K multiplied by the number of games in a rating period exceeds 700, K becomes the largest whole number that keeps the product at or under 700. A K = 40 player who plays 20 rated games in one month is rated with K = 35. The calculator applies this automatically.
The 400-Point Rule
A rating difference of more than 400 points is counted as 400 (rule 8.3.1). A 1500 player who meets a 2100 player is rated as if the gap were 400, so the expected score is 0.08. With K = 40 a win earns +36.8, rounded to +37, and a loss costs −3.2, rounded to −3.
Since 1 October 2025 the rule applies only to players rated below 2650. At 2650 or above the full difference counts in standard chess: a 2700 who beats a 2200 has an expected score of 0.96 and, at K = 10, gains +0.4, which rounds to 0.
Rapid and blitz keep the 400-point rule for everyone, with one addition from 1 December 2024: a game between players 600 or more points apart is not rated at all when either of them is rated above 2600. Choose "Rapid or blitz" in the calculator to apply both.
Rounding: Once per Rating Period, Not per Game
FIDE rounds the total change for the rating period, one calendar month, not each game, and rounds 0.5 away from zero (rule 8.3.4). That is why this calculator rates everything you enter as one period, shows each game's share unrounded, and rounds only the total.
It can make a real difference. A 2410 player with K = 10 who beats three opponents rated 2300 expects 0.65 in each game, so each win is worth +3.5. Rounded once, the total of +10.5 becomes +11. Rounded game by game it would be +12. To match FIDE, enter every rated game from the same month together, even if they came from two different tournaments.
FIDE Elo vs Chess.com and Lichess Ratings
FIDE: Elo
A fixed K-factor, expected scores from one table, and a new list on the first day of each month. Only games in FIDE-rated events count, and the lowest published rating is 1400.
Chess.com and Lichess: Glicko
Chess.com uses Glicko and Lichess uses Glicko-2, both designed by Mark Glickman. Instead of a fixed K, each rating carries a deviation that says how sure the system is. New or inactive accounts swing by large amounts; established ones move a few points a game. Ratings update after every game.
Each site rates a different pool of players under different time controls, so a 1500 on Lichess, a 1500 on Chess.com and a 1500 FIDE rating are three different levels. Use this calculator for FIDE arithmetic only. For what the numbers mean in practice, read what a chess ELO rating is and what counts as a good one.
Performance Rating
The calculator also shows your tournament performance: the average rating of your opponents plus the rating difference FIDE's table 8.1.1 gives for your percentage score. Score 6 out of 9 (67%) against an average of 1900 and the table adds 125, a performance of 2025. A 100% score has no exact performance, so FIDE's table counts it as 800 points above the average, and 0% as 800 below.
Raise the Number
The calculator tells you what a result is worth. Getting the results is the hard part.
Frequently Asked Questions
How is a FIDE rating change calculated?
For each game, take your score (1 for a win, 0.5 for a draw, 0 for a loss) minus your expected score from FIDE's table. Add those up over the rating period (one calendar month of rated games), multiply by your K-factor and round to the nearest whole number. Beating a player rated 100 points above you with K = 20 gives 20 × (1 − 0.36) = +12.8, which rounds to +13.
Which K-factor should I use?
Use K = 40 if you have fewer than 30 FIDE-rated games, or if you are a junior rated under 2300 (until the end of the year you turn 18). Use K = 10 once your published rating has reached 2400, even if it has dropped since. Everyone else uses K = 20. The same rules apply to the rapid and blitz lists.
How many points do I get for beating a higher-rated player?
It depends on the gap and your K. With K = 20, beating someone 100 points higher earns +13, 200 points higher +15, and 400 or more points higher +18. Losing to the same players costs 7, 5 and 2 points.
Why did I lose rating points after a draw?
Because you were expected to score more than half. Against a player 150 points below you, FIDE's table expects 0.70 from you. A draw scores 0.5, so at K = 20 you lose 20 × (0.70 − 0.5) = 4 points. If your opponent's K is also 20, they gain the same amount.
What is the 400-point rule in FIDE ratings?
A rating difference of more than 400 points is counted as 400 (FIDE Rating Regulations, 8.3.1). The expected score therefore never goes past 0.92, so at K = 20 a heavy favourite still gains 1.6 points for a win and the underdog still loses 1.6 for a loss. Since 1 October 2025 the rule applies only to players rated below 2650; for players at 2650 or above the full difference is used in standard chess.
Is my Chess.com or Lichess rating the same as a FIDE rating?
No. Chess.com uses the Glicko system and Lichess uses Glicko-2, each with its own pool of players, so the numbers do not convert reliably into each other or into FIDE. This calculator gives FIDE's arithmetic; for a rough idea of your playing strength, take the chess ELO test.
When does a new FIDE rating appear?
FIDE publishes a new rating list on the first day of every month. It includes the rated games from the rating period before it, so your change shows up on the list after the tournament has been reported.