How Chess Ratings Work - The Elo System
Understand the math behind your chess rating and what it actually measures.
Published 2026-02-01 | Last verified 2026-02-12
Professor Archer says: The Elo system is elegant in its simplicity. Beat a higher-rated player, gain more points. Lose to a lower-rated player, lose more points. It rewards you for facing strong opposition and penalizes you for stumbling against weaker opponents.
The Origin of the Elo System
The Elo rating system was developed by Arpad Elo, a Hungarian-American physics professor and chess player. FIDE adopted it in 1970, and it has been the standard for measuring chess strength ever since.
The system is based on a simple idea: the difference in ratings between two players predicts the expected outcome of their game. A player rated 200 points higher than their opponent is expected to score about 75 percent.
How Rating Points Are Calculated
After each game, your rating changes based on the difference between your actual result and the expected result. If you beat someone you were expected to beat, you gain a small number of points. If you beat someone much higher-rated, you gain many more.
The formula uses a K-factor, which determines how much your rating can change per game. New players have a higher K-factor so their rating adjusts quickly to their true level. Experienced players have a lower K-factor, making their rating more stable.
The key insight is that the system is self-correcting. If your rating is too low, you will win more than expected and your rating will rise. If it is too high, you will lose more and it will fall. Over time, your rating converges on your true playing strength.
What Your Rating Actually Means
A chess rating is a relative measure. It tells you how you perform against other rated players in the same system. A 1500-rated player is expected to beat a 1300-rated player about 75 percent of the time.
Here are rough benchmarks: below 1000 is a beginner learning the fundamentals, 1000 to 1400 is a casual player with basic tactical ability, 1400 to 1800 is a solid club player, 1800 to 2200 is a strong club player or candidate master, and above 2200 is expert to master level.
Remember that ratings vary by platform and organization. An 1800 rating on one platform might correspond to a very different strength than 1800 on another.
Rating System FAQ
Can my rating go below zero?
In most systems, ratings have a practical floor. FIDE does not publish ratings below 1000, and most online platforms have a minimum around 100 to 400. Your displayed rating will not go negative.
Why does my rating change different amounts for different games?
The change depends on the expected outcome. Beating a much higher-rated player earns more points because it was an upset. Losing to a much lower-rated player costs more for the same reason.
What is the K-factor?
The K-factor controls how quickly your rating changes. A higher K-factor means bigger swings per game. New players typically have K=40, while experienced players might have K=10 or K=20.
Professor Archer says: Your rating is a snapshot, not a verdict. It changes every time you play. Focus on learning, and the rating will follow. I have never met a player who improved their understanding and saw their rating go down permanently.
Quick Quiz
If a 1600-rated player beats a 1400-rated player, how many rating points would they typically gain?
- A large number, because they won - The number of points depends on the expected outcome. Beating a lower-rated player was expected, so the gain is small.
- A small number, because the win was expected (Correct) - Correct. The 1600 player was expected to win against a 1400, so the rating gain is modest - typically around 5 to 8 points depending on the K-factor.
- Zero points, because the opponent was weaker - You always gain some points for a win, regardless of the opponent's rating. The amount is just smaller when you beat a lower-rated player.
- Exactly 16 points every time - Rating changes are not fixed. They depend on the rating difference and the K-factor.