Free tool
Swiss tournament rounds calculator
How it works
Enter your player count. The minimum number of Swiss rounds is log2 of the players, rounded up, because each round roughly halves the group on a perfect score. 24 players need 5 rounds; add one or two more when prizes go several places deep.
Minimum rounds
5
So one player can finish on a unique perfect score
Recommended for prizes
6 to 7
Extra rounds separate the places behind first
Games per player
5
12 boards per round
The rule of thumb is rounds = log2(players), rounded up: each round halves the perfect scores, so 5 rounds cleanly separates up to 32 players. Add a round or two when trophies go several places deep, and use an odd player count plan for byes.
The method behind the numbers
Minimum rounds = ceil(log2(players))
A Swiss event pairs players on similar scores each round without eliminating anyone. After each round the number of perfect scores roughly halves, so you need enough rounds for at most one perfect score to remain: that is the log2 rule.
The minimum produces a clear winner but often leaves ties just below first. If your event awards trophies to several places, or age-group prizes inside the open field, one or two extra rounds plus standard tie-breaks separate the standings far better than tie-breaks alone.
With an odd number of players, one player receives a bye each round (a free point in most regulations). Academies running internal Swisses should rotate byes to the lowest-scoring eligible player and publish that rule before round one.
Frequently asked questions
How many rounds for 16, 32, or 64 players?
The minimums are 4, 5, and 6 rounds: each is exactly log2 of the player count because those are powers of two. For prize fairness most organizers run one extra round, so a 32-player weekend event typically plays 6.
Why not just run a knockout instead?
A knockout sends half the field home after one game, which is a poor experience for students and parents who travelled for a day of chess. A Swiss gives every player a full schedule of games against similar scores, which is why it dominates amateur and scholastic chess.
What happens when two players have the same final score?
Tie-break systems decide the order: common ones compare the strength of the opposition each player faced, such as Buchholz, or use direct encounter first. Publish the tie-break order in the event regulations before the tournament starts to avoid podium arguments.
Keep going
Start building a smarter academy
Early access — we set up your academy with you: roster import, Lichess and Chess.com connections, batches, and fee plans.