A single round robin has one matchup for every possible pair of participants. The formula is n x (n - 1) / 2, where n is the number of teams or players.
How many games are in a round robin? Quick answer
Use n x (n - 1) / 2 for a single round robin. If you have 8 teams, the math is 8 x 7 / 2, so the schedule has 28 games. If you have 10 teams, the schedule has 45 games.
Use the Round Robin Generator when you want the match list, rounds, byes, courts, and start times generated from your actual team names.
How to calculate round robin games
- 4 teams: 6 games
- 5 teams: 10 games
- 6 teams: 15 games
- 7 teams: 21 games
- 8 teams: 28 games
- 10 teams: 45 games
- 12 teams: 66 games
For a double round robin, double those totals because each pair plays twice. For example, 6 teams make 15 games in a single round robin and 30 games in a double round robin.
Why the n x (n - 1) / 2 formula works
Each participant can play n - 1 opponents. Multiplying n by n - 1 counts every matchup twice, once from each participant's side. Dividing by 2 leaves the actual number of games.
What is the difference between round robin games and rounds?
Games are total matchups. Rounds are the blocks of time needed to run them. Six teams need 15 games across 5 rounds. Seven teams need 21 games across 7 rounds because one team has a bye each round.
Even team counts usually need n - 1 rounds. Odd team counts usually need n rounds because one participant is idle each round. That means a 5-team round robin has 10 games across 5 rounds, while a 6-team round robin has 15 games across 5 rounds.
How many courts do I need for a round robin?
Courts do not change the number of games. They change how quickly you can finish the schedule. An 8-team round robin still has 28 games whether you have one court or four courts.
To estimate time, divide matches per round by available courts, then multiply by match length. Four matches in a round on two courts need two time slots. With 25-minute matches, that round needs about 50 minutes before breaks.
How long a round robin schedule will take
First calculate matches per round, then divide by courts. If eight teams create four matches per round and you have two courts, each round needs two match slots. With 25-minute matches, each round needs about 50 minutes before breaks.
Add setup time, finals or placement games, and buffer time for late starts. A spreadsheet-style game count is useful, but the venue schedule is what determines whether the format is realistic.
When to use pools instead of a full round robin
If the number of games is too large, use pools, shorten match length, add courts, or switch to a bracket. Do not force a full round robin if the schedule becomes too long for the venue.
Pools are often the clean compromise. Instead of one 12-team round robin with 66 games, split into two 6-team pools for 30 pool games total, then run semifinals and a final. That reduces total matches while still giving teams several guaranteed games.
Quick formula table
- Single round robin games: n x (n - 1) / 2.
- Double round robin games: n x (n - 1).
- Even-team rounds: n - 1.
- Odd-team rounds: n, with one bye each round.
- Matches per round: even n is n / 2; odd n is (n - 1) / 2.
Quick answers
How many games are in an 8-team round robin? 28 games.
How many games are in a 10-team round robin? 45 games.
Does a double round robin double the games? Yes. Each pair plays twice, so an 8-team double round robin has 56 games.
How many rounds are in a 7-team round robin? Seven rounds, with one team resting each round.
What if the round robin has too many games? Use pools, add courts, shorten match length, or switch to a bracket or hybrid pool-to-bracket format.