Tournament Bracket Calculator

Always one fewer than the number of entrants. Every match eliminates exactly one person, and all but the winner must be eliminated — so 64 entrants need 63 matches regardless of the bracket layout.

A free pass to the second round, given when the entry count is not a power of two. A 13-entrant tournament uses a 16-slot bracket, so three entrants receive byes.

The top seeds. Byes reduce the number of matches a strong entrant must win, which is the point of seeding — it keeps the strongest entrants apart until the later rounds.

The base-2 logarithm of the bracket size, rounded up: 16 entrants take four rounds, 64 take six. Each round halves the field.

Entrants are removed after two losses, using a losers' bracket. It takes roughly twice the matches and is much fairer to someone who has a single bad match early.

It adds one match and gives the losing semi-finalists something to play for. Many tournaments include one; some regard it as a match nobody wants to play.

Strongest entrants are placed so they meet as late as possible — one against the lowest seed, two at the opposite end of the bracket. It is designed to make the final the best available match.

A secondary bracket for entrants eliminated early, so they get more matches. It roughly doubles the fixtures and is common in junior and amateur tournaments for that reason.

Because it is the shortest possible format that produces an undefeated winner. It is also the most vulnerable to a single upset, which is a feature commercially and a flaw competitively.

Six, since 2 to the power 6 is 64. Each round halves the field: 32, 16, 8, 4, 2, 1.

An extra round to reduce an awkward entry count to a power of two, rather than giving byes. It is fairer in one sense and asks some entrants to play an extra match.

Generally not — byes should follow seeding, since randomly advantaging a weak entrant undermines the point of the bracket. Randomising is only fair if there is no seeding at all.