Hong Life CalculatorsUnderstanding the goalkeeper save percentage calculator — concept and principle
Save percentage and goals against average (GAA) are the two classic goalkeeper numbers in soccer and ice hockey. Save percentage tells you how often a keeper stops a shot on target; GAA tells you how many goals the team concedes per full game while that keeper is in net. They let you compare keepers with different workloads.
How it is calculated
- Save % = saves ÷ (saves + goals against) × 100. Saves plus goals is the number of shots on target faced.
- GAA = goals against ÷ minutes played × game length.
Use 90 for game length in soccer and 60 in ice hockey. Minutes are the minutes the keeper actually played, so a keeper subbed off at half time adds 45, not 90.
The principle
A shot on target has only two outcomes for a goalkeeper: it is saved or it goes in. That is why the shots faced can be rebuilt from saves plus goals. Save percentage is then a simple success rate. GAA is a rate per game, built the same way as any per-90 or per-60 statistic: divide by playing time to get goals per minute, then multiply by the length of a full game. The two numbers answer different questions. Save % mostly reflects the keeper. GAA mixes the keeper with the defence in front of them, because a team that allows few shots will have a low GAA even with an average keeper.
Worked example
Defaults: 90 saves, 25 goals against, 2,700 minutes, game length 90.
- Shots on target faced = 90 + 25 = 115.
- Save % = 90 ÷ 115 × 100 = 78.26%.
- Games played = 2,700 ÷ 90 = 30.
- GAA = 25 ÷ 2,700 × 90 = 0.833 goals per game.
| Saves | Save % |
|---|---|
| 22.5 | 47.37% |
| 45 | 64.29% |
| 67.5 | 72.97% |
| 90 | 78.26% |
| 112 | 81.82% |
| 135 | 84.38% |
| 180 | 87.8% |
How to read the result
In top soccer leagues the average save percentage is usually around 70%, so 78% is clearly above average. A GAA under 1.0 in soccer is very good, but check how many shots the defence allows before giving the keeper all the credit. In the NHL, save percentage is written as a decimal like .910 and league averages in recent seasons have been close to .900–.910. Many analysts now also use post-shot expected goals (PSxG) minus goals allowed, which accounts for how hard each shot was to save.
Common mistakes
- Counting own goals as shots faced; own goals are not shots on target and are usually left out of save %.
- Using team minutes instead of the keeper's own minutes for GAA.
- Comparing hockey and soccer numbers directly; shot volume and save rates are very different.
- Judging a keeper on a few games; save % is noisy over short samples.
Frequently asked questions
Does a penalty save count?
Yes. A penalty on target that is saved counts as a save, and a scored penalty counts as a goal against.
Why does hockey save % look so much higher?
Hockey teams shoot often from distance, and many shots are routine for the goalie, so about nine in ten are stopped. Soccer has fewer shots, and more of them are clear chances.
What does a GAA of 0.83 mean?
About five goals conceded every six full games with this keeper in goal.
Sources: IFAB Laws of the Game (match duration: two halves of 45 minutes) · NHL official statistics – save percentage and goals against average