Your Handicap Index measures your potential, not your average. Under the World Handicap System (WHS), it comes from your best recent score differentials. You can calculate it by hand in three steps, or use our golf handicap calculator.
Step 1: calculate each score differential
A score differential adjusts a round for how hard the course was. The formula is:
Example: you shoot an adjusted gross score of 88 on a course with a rating of 71.2 and slope of 128. The differential is (113 / 128) x (88 - 71.2) = 0.8828 x 16.8 = 14.8.
Step 2: pick your best differentials
Your Handicap Index uses your most recent 20 scores. It takes the average of the lowest eight differentials. If you have fewer than 20 scores, fewer are used:
| Scores available | Differentials used | Adjustment |
|---|---|---|
| 3 | Lowest 1 | -2.0 |
| 4 | Lowest 1 | -1.0 |
| 5 | Lowest 1 | 0 |
| 6 | Average of lowest 2 | -1.0 |
| 7 to 8 | Average of lowest 2 | 0 |
| 9 to 11 | Average of lowest 3 | 0 |
| 12 to 14 | Average of lowest 4 | 0 |
| 15 to 16 | Average of lowest 5 | 0 |
| 17 to 18 | Average of lowest 6 | 0 |
| 19 | Average of lowest 7 | 0 |
| 20 | Average of lowest 8 | 0 |
Step 3: average and round
Add the selected differentials, divide by how many you used, apply any adjustment, and round to one decimal. The maximum Handicap Index is 54.0.
From Handicap Index to Course Handicap
Your Handicap Index is portable. On any course, your Course Handicap = Handicap Index x (Slope / 113) + (Course Rating - Par). Try it with the course handicap calculator.
Wondering what the numbers mean? Read what a golf handicap is and course rating and slope.
Frequently asked questions
How many scores do I need for a handicap?
Under the World Handicap System you need at least 54 holes of scores, for example three 18-hole rounds.
Is my Handicap Index my average score?
No. It reflects your potential based on your best recent differentials, so it is lower than your average.
What is the maximum Handicap Index?
54.0 for all players.
