League handicap calculator

How it works

Both methods start from an adjusted score: your gross score with each hole capped at net double bogey, which is par plus 2 plus any strokes you receive on that hole. One blow-up hole then cannot wreck your number. If you only have gross scores, lower any big hole first.

Method A, the differential average, is the default. Each round becomes a differential, which says how far above the course rating you scored after adjusting for how hard the course is. The league handicap is the average of your lowest 4 differentials from your most recent 8 rounds. You can change both numbers. Method B is simpler: your average score over par across your last 5 rounds, times 80%. It ignores course difficulty, which suits a league that plays one course every week.

1. Differential (Method A) = 113 divided by the slope, times (adjusted score minus course rating), rounded to a tenth. In a nine-hole round use the nine’s own rating and slope, then double the result so it sits on the 18-hole scale.
2. League handicap (Method A) = the average of the lowest 4 differentials among your last 8 rounds, to a tenth.
3. With fewer than 8 rounds a sliding rule counts fewer: 1 to 3 rounds count 1, 4 or 5 rounds count 2, 6 or 7 rounds count 3, and 8 or more rounds count 4.
4. Over par (Method B) = adjusted score minus par, doubled for a nine-hole round. League handicap = the average over your last 5 rounds times 80%, to a tenth.
5. Nine-hole playing number = half the league handicap. In Method A, convert it with the nine you are playing: half the handicap times slope divided by 113, plus course rating minus par. Round once, and a half rounds up.

A league handicap lives on the 18-hole scale. That is why a nine-hole differential is doubled on the way in and the number is halved when you play nine. Rounding happens once, at the end.

Worked example: eight rounds on the back nine

A golfer in a nine-hole league has posted eight adjusted scores on a back nine with a course rating of 34.9, a slope of 123 and a par of 36: 44, 46, 43, 47, 45, 42, 44, 48, oldest first. Using Method A with the default best 4 of the last 8.

Take round 1. 44 minus 34.9 is 9.1. Times 113 divided by 123 is 8.36. Doubled for the 18-hole scale it is 16.72, which rounds to 16.7. Repeat for every round, then keep the lowest 4: 13.0, 14.9, 16.7, 16.7. Their total is 61.3, and 61.3 divided by 4 is 15.325, so the league handicap is 15.3.

For a nine-hole round on that same nine, half the league handicap is 7.65. Times 123 divided by 113, plus 34.9 minus 36, rounds once to a nine-hole playing number of 7. Switch the same eight rounds to Method B, last 5 rounds at 80%, and the league handicap comes out at 14.7.

When to use it

• Setting starting handicaps before the first week, from a few rounds each golfer already has.
• Checking one golfer’s number when someone asks how it was figured. Every counted round is highlighted.
• Comparing Method A and Method B on your own league’s scores before you pick one for the season.
• Giving a sub or a new golfer a temporary number so they can play for the week.
• It is not for tournament entries, club competitions or anything that needs an official handicap. Those come from the golfer’s club or golf association.