Golf Handicap Calculator
Enter 3 to 20 rounds: your score, and the course rating and slope of the tee you played. You get each round's differential and an estimated Handicap Index, with the rounds that count highlighted.
Your handicap says how many shots. golfity shows where they go: strokes gained from every round you log.
Estimated Handicap Index
An unofficial estimate. It skips the net double bogey hole limit, the playing conditions calculation and the caps against your low index. Your official Handicap Index comes from your national association: the USGA, England Golf, the RFEG.
Add a round from a course
Five example rounds. Replace them with yours, oldest first.
Now work out your course handicap for any tee →
Your handicap says how many shots. golfity shows where they go: strokes gained from every round you log.
How a Handicap Index Is Calculated
Every round is turned into a score differential, one decimal place:
Differential = (113 ÷ Slope) × (Score − Course Rating)
A 92 on a tee rated 72.1 with a slope of 130 is (113 ÷ 130) × 19.9 = 17.3. Your index is then built from your lowest differentials. How many count depends on how many rounds you have:
| Rounds | Differentials used | Adjustment |
|---|---|---|
| 3 | Lowest 1 | −2.0 |
| 4 | Lowest 1 | −1.0 |
| 5 | Lowest 1 | – |
| 6 | Average of lowest 2 | −1.0 |
| 7–8 | Average of lowest 2 | – |
| 9–11 | Average of lowest 3 | – |
| 12–14 | Average of lowest 4 | – |
| 15–16 | Average of lowest 5 | – |
| 17–18 | Average of lowest 6 | – |
| 19 | Average of lowest 7 | – |
| 20 | Average of lowest 8 | – |
The result is rounded to one decimal and capped at 54.0. With 20 rounds, a golfer whose best 8 differentials average 15.1 has a 15.1 index, even if their typical round is several shots higher. That is by design: an index measures your potential, not your average. What that means in scores is in what does a 15 handicap shoot.
Why This Is an Estimate
The official calculation starts from your adjusted gross score, with each hole capped at net double bogey. It adds a playing conditions adjustment when a whole field scores unusually high or low, and soft and hard caps that slow how far your index can rise above your lowest of the past 12 months. None of that can be worked out from a total score, so the number above is a close estimate, not an official index. Your official Handicap Index comes from your national association: the USGA, England Golf, the RFEG or their equivalent.
The step-by-step version, worked out by hand, is in how to calculate your golf handicap. Once you have an index, the course handicap calculator turns it into strokes for any tee.
Common Questions
How is a golf handicap calculated? +
Each round becomes a score differential: (113 ÷ slope) × (score − course rating). Your Handicap Index is the average of the lowest 8 of your most recent 20 differentials. With fewer than 20 rounds a smaller number counts, and with 3, 4 or 6 rounds a small adjustment is subtracted. The index is capped at 54.0.
How many rounds do I need for a handicap? +
Three 18-hole rounds, or 54 holes in any mix of 9 and 18, are enough for a first Handicap Index. It is based on fewer rounds until you have 20, so it moves a lot early on. From 20 rounds the index always uses your best 8 of the last 20.
What is a score differential? +
It is one round expressed on a course of standard difficulty. Shoot 92 on a tee rated 72.1 with a slope of 130 and the differential is (113 ÷ 130) × (92 − 72.1) = 17.3. The 113 ÷ slope part shrinks a score made on a hard course and stretches one made on an easy course.
Why is my official handicap different from this estimate? +
Your association works from your adjusted gross score, where every hole is capped at net double bogey, and it applies a playing conditions adjustment on days when scoring was unusually high or low. It also limits how fast your index can rise above your lowest index of the past year. This calculator uses your total score with none of those, so treat it as an estimate.
Can I use 9-hole rounds? +
Not directly here. Under the World Handicap System a 9-hole score is combined with an expected score for the other nine to make an 18-hole differential. For an estimate, add two 9-hole scores from the same course together and enter them with that course’s 18-hole rating and slope.
Your Handicap in Context
Course Handicap Calculator
Turn your index into strokes for any tee, from our course database or the scorecard.
What Is a Good Golf Handicap?
Where your index ranks, and what a scratch, 10, 20 and 30 actually shoot.
What Does a 10 Handicap Shoot?
84 to 87 on average, and how that compares with every handicap from scratch to 30.
Strokes Gained Calculator
Your handicap is how many shots. Strokes gained shows which part of your game they come from.
See Where the Shots Go
Your handicap says how many shots. golfity shows where they go: strokes gained from every round you log.