Sports
Golf Handicap Calculator
Enter your recent rounds with their course and slope ratings to get a handicap index from the best differentials.
Calculation inputs
Enter up to 20 rounds — leave unused rows blank.
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Complete the fields and select Calculate to show results here.
About this calculator
A golf handicap calculator estimates a player's handicap index from a set of recent rounds, using the same differential-based approach outlined by the USGA. Golfers use it to compare skill levels and set fair competition across different courses.
How the calculation works
- Differential = (score − course rating) × 113 ÷ slope rating
- The best differentials are selected based on how many rounds you entered (1 of 3, up to 8 of 20)
- Handicap index = average of the selected differentials × 0.96
Notes and assumptions
An official index comes from your golf association using posted, peer-reviewed scores — this is an unofficial estimate of the same calculation.
113 is the standard slope rating for a course of average difficulty.
How it works in plain English
Each round you play produces a score differential, a number that adjusts your raw score for the difficulty of the course and tee you played, expressed through the course rating and slope rating printed on most scorecards. The differential formula scales the gap between your score and the course rating by a standard slope factor, so a good round on a hard course counts more than the same score on an easy one.
Once you have differentials from a set of recent rounds, the handicap index is built from the average of the best differentials among them, not every round played. The official system uses a sliding scale: the number of differentials used and the number averaged both depend on how many total rounds are on file, so a player with only a handful of rounds is treated differently than one with a long history.
The result is expressed as a single index number, generally lower for stronger players, which can then be converted into a course handicap for a specific tee using that course's own slope rating.
The formula
- Score differential = (adjusted gross score - course rating) x 113 / slope rating
- Handicap index = average of the best differentials from recent rounds
Worked example
Suppose a golfer shoots 92 on a course with a rating of 71.5 and a slope of 128. The differential is (92 - 71.5) x 113 / 128 = 20.5 x 0.883 = about 18.1.
If this golfer's best differentials from their last 20 rounds average out to 17.4, that becomes their handicap index. On a course with a higher slope rating, this index converts to a course handicap of a few strokes higher than the index itself, reflecting that course's extra difficulty.
Suppose that same golfer plays a tougher course with a slope of 145. The course handicap formula scales the index by that slope relative to a standard 113, so 17.4 x (145 / 113) rounds to about 22 strokes for that specific tee. On an easier course with a slope of 110, the same 17.4 index would convert to roughly 17 strokes, showing how the same underlying skill level translates into a different number of strokes depending on where it's played.
Rounds used to calculate a handicap index
| Rounds on file | Differentials used |
|---|---|
| 3-5 | Lowest 1 |
| 6-8 | Lowest 2 |
| 9-11 | Lowest 3 |
| 12-14 | Lowest 4 |
| 15-16 | Lowest 5 |
| 17-18 | Lowest 6 |
| 19 | Lowest 7 |
| 20 | Lowest 8, averaged |
Reflects the sliding scale used in the USGA World Handicap System.
Frequently asked questions
What are course rating and slope rating?
Course rating estimates the expected score for a scratch (zero-handicap) golfer on that course, while slope rating measures relative difficulty for a bogey golfer compared to a scratch golfer. Both numbers are set by course raters and printed on the scorecard for each set of tees.
Why isn't my handicap just the average of all my scores?
The system only averages your best differentials rather than all of them, which accounts for the fact that most golfers occasionally play a round well below their typical potential, and the index is meant to reflect potential ability, not a season-long average.
What's the difference between handicap index and course handicap?
Handicap index is a portable number reflecting general skill, unaffected by any single course. Course handicap converts that index for a specific course and tee using its slope rating, giving the actual number of strokes you'd receive there.
How many rounds do I need before I get a handicap index?
The official system allows an index to be calculated from as few as three rounds, though it becomes more stable and representative as more rounds are added, since it can then draw from a larger pool of differentials.
Can a handicap index go up as well as down?
Yes. Because it's based on a rolling set of recent rounds, a stretch of higher scores will raise the index just as a stretch of lower scores will lower it, so it moves in both directions over time.