# What is my golf handicap?

Computes a golf Handicap Index by the World Handicap System from up to 20 recent 18-hole scores with their course and slope ratings, and the course handicap for a chosen course.

- Page: https://www.acalculator.org/sports/golf-handicap-calculator
- JSON spec: https://www.acalculator.org/sports/golf-handicap-calculator.json
- Version: 0b2e1329ef28

## Default answer

Example with the default inputs (Your rounds [Adjusted gross score 85, Course rating 69.3, Slope rating 125; Adjusted gross score 95, Course rating 73.5, Slope rating 130; Adjusted gross score 88, Course rating 71.2, Slope rating 128; Adjusted gross score 92, Course rating 72, Slope rating 131; Adjusted gross score 90, Course rating 70.5, Slope rating 124]): Your Handicap Index is 14.2; score differentials used: 1.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| rounds | Your rounds | Your most recent 18-hole rounds, up to 20: each adjusted gross score with the course rating and slope rating of the tees played. |
| cs | Slope rating | The slope rating of the tees you will play, for the course handicap. |
| ccr | Course rating | The course rating of the tees you will play. |
| par | Par | The par of the course from those tees. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| index | Handicap Index | The average of your lowest score differentials plus the table adjustment, to the nearest tenth, at most 54.0; below 0 is a plus handicap. |
| used | Differentials used | How many of your lowest score differentials count (Rule 5.2a table). |
| adjustment | Adjustment | The strokes the Rule 5.2a table adds with 3, 4 or 6 scores: −2.0, −1.0 or −1.0. |
| average | Average of the lowest | The average of the lowest score differentials before the adjustment and rounding. |
| differentials | Score differentials | Each round’s score differential, rounded to the nearest tenth, in the order entered. |
| lowest | Lowest differentials used | The differentials that count, from lowest up. |
| courseHandicap | Course handicap | Handicap Index × slope rating ÷ 113 + (course rating − par), to the nearest whole stroke. |

## Method

score differential = (113 ÷ slope rating) × (adjusted gross score − course rating − PCC), rounded to 0.1; Handicap Index = average of the lowest differentials (Rule 5.2a) + adjustment, rounded to 0.1, at most 54.0.

## Assumptions

- Follows the World Handicap System, Rules of Handicapping effective January 2024 (USGA and R&A): Rules 5.1, 5.2 and 6.1a.
- Enter 18-hole rounds only, 3 to 20 of them, most recent first or last: all rounds entered count as your scoring record. 9-hole scores are not combined here.
- Scores are adjusted gross scores: each hole already capped at net double bogey.
- The exceptional score reduction and the soft and hard caps, which need your handicap history, are not applied.
- Every step is exact; a value exactly halfway rounds up (toward plus infinity), so 5.65 is 5.7 and −5.65 is −5.6.

## Worked examples

1. rounds = {"score":85,"rating":69.3,"slope":125} or {"score":95,"rating":73.5,"slope":130} gives index = 12.2, used = 1, adjustment = -2, differentials = 14.2, 18.7, 14.8, lowest = 14.2, average = 14.2. Source: USGA Handicap System manual, Section 10 (113 ÷ 125 × (85 − 69.3) = 14.2), https://www.usga.org/custom-search-pages/rules/handicap-manual/rule-14389.html; SCGA, How is a Handicap Index calculated? ((95 − 73.5) × 113 ÷ 130 = 18.7), https://help.scga.org/knowledge/how-is-a-handicap-index-calculated; Rules of Handicapping 2024, Rule 5.2a (3 differentials: lowest 1, −2.0).
2. rounds = {"score":85,"rating":69.3,"slope":125} or {"score":95,"rating":73.5,"slope":130} gives index = 12.7, used = 2, adjustment = -1, lowest = 13.2, 14.2, average = 13.7. Source: Rules of Handicapping 2024, Rule 5.2a (6 differentials: average of the lowest 2, −1.0).
3. rounds = {"score":80,"rating":73.5,"slope":130} or {"score":67,"rating":73.5,"slope":130} gives differentials = 5.7, -5.6, -1.0, lowest = -5.6, index = -7.6. Source: USGA Rules of Handicapping, Rule 5.1c, rounding of minus score differentials (−1.55 rounds to −1.5), https://www.usga.org/content/usga/home-page/handicapping/roh/Content/rules/5%201c%20Calculation%20of%20a%20Score%20DifferentialRoundingMinus.htm.
4. rounds = {"score":85,"rating":69.3,"slope":125} or {"score":95,"rating":73.5,"slope":130}, cs = 135, ccr = 72.4, par = 72 gives index = 14.2, used = 1, courseHandicap = 17. Source: Rules of Handicapping 2024, Rule 6.1a (Course Handicap = Handicap Index × Slope Rating ÷ 113 + (Course Rating − par)).

## FAQ

### How is a golf handicap calculated?

For each round, the score differential is (113 ÷ slope rating) × (adjusted gross score − course rating − PCC), rounded to one decimal. The Handicap Index is the average of your lowest 8 differentials out of your most recent 20, rounded to one decimal. With fewer than 20 scores a table decides how many count.

### What is a score differential?

It measures one round against the course’s difficulty. A score of 95 on a course rated 73.5 with a slope of 130 gives (95 − 73.5) × 113 ÷ 130 = 18.69, so the differential is 18.7.

### How many scores do I need for a handicap?

Three 18-hole scores. With 3 scores the Handicap Index is your lowest differential minus 2.0; with 4 it is the lowest minus 1.0; with 5 the lowest; with 6 the average of the lowest 2 minus 1.0; and more scores use more differentials, up to the lowest 8 of 20.

### What is the adjusted gross score?

Your score after each hole is capped at net double bogey: par + 2 + any handicap strokes you get on that hole. It keeps one very bad hole from raising your handicap too much. Enter scores after this adjustment.

### What is the difference between a Handicap Index and a course handicap?

The Handicap Index travels with you; the course handicap is the strokes you get from a particular set of tees: Handicap Index × slope rating ÷ 113 + (course rating − par). A 14.2 index on tees rated 72.4 with a slope of 135 and par 72 gives 14.2 × 135 ÷ 113 + 0.4 = 17.36, a course handicap of 17.

### What does a negative Handicap Index mean?

It is a plus handicap, written with a plus sign in golf: an index of −1.2 is shown as +1.2 on a handicap card. It means you usually score better than the course rating, and you give strokes back to the course.

### Is this my official handicap?

No. An official Handicap Index comes from your golf association, which also applies the exceptional score reduction and the soft and hard caps from your handicap history. This calculator gives the basic calculation so you can check it or estimate one.

## Sources

- USGA and The R&A, Rules of Handicapping, effective January 2024: Rule 5.1 (score differential), Rule 5.2 (calculation of a Handicap Index, the table in 5.2a, maximum 54.0), Rule 6.1a (course handicap). https://www.usga.org/content/dam/usga/pdf/2024-revision/2024-Rules-of-Handicapping-USGA.pdf
- USGA, Rules of Handicapping, Rule 5.1c, Rounding of Minus Score Differentials (−1.54 and −1.55 round to −1.5, −1.56 to −1.6). https://www.usga.org/content/usga/home-page/handicapping/roh/Content/rules/5%201c%20Calculation%20of%20a%20Score%20DifferentialRoundingMinus.htm
- The R&A, Rules of Handicapping, Rule 5 (lowest 8 of the most recent 20; maximum Handicap Index 54.0). https://www.randa.org/en/roh/the-rules-of-handicapping/rule-5
- SCGA Help Desk, How is a Handicap Index calculated? (worked example: 95, 73.5 / 130 gives 18.7). https://help.scga.org/knowledge/how-is-a-handicap-index-calculated