Knockout Rounds Calculator

Work out knockout rounds instantly with clear inputs, formula shown and shareable results.

About Knockout Rounds Calculator

The number of rounds is the base-two logarithm of the entry count rounded up, and every knockout needs entrants minus one ties regardless of how they are seeded. Doubling the field adds only one round, which is why a 64 team draw takes six rounds and a 128 team draw takes seven.

Formulas

Rounds

rounds = ceiling(log2(entrants))

Games

games = (entrants - 1) x 2 for two-legged ties

Worked example

With the default values below, Knockout Rounds Calculator returns Rounds needed of 6. Change any input above and every figure here is recalculated in your browser.

Inputs used

Number of entrantsminimum 2: 64
Two-legged ties: Yes

Results

Rounds needed: 6
Ties to be decided: 63
Individual games played: 126
Byes required: 0

Step by step

1Values used
2Rounds
3Games
4Rounds needed= 6
5Ties to be decided= 63
6Individual games played= 126
7Byes required= 0

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Knockout Rounds figure worked out?

rounds = ceiling(log2(entrants)). The number of rounds is the base-two logarithm of the entry count rounded up, and every knockout needs entrants minus one ties regardless of how they are seeded.

Why does this matter?

Doubling the field adds only one round, which is why a 64 team draw takes six rounds and a 128 team draw takes seven.

What do I need to enter?

Enter number of entrants, two-legged ties. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.