Calculate your World Handicap System (WHS) Handicap Index from recent scores, course rating, and slope rating.
Enter your recent rounds. Handicap uses the best differentials from your entries.
| # | Score | Course Rating | Slope Rating | Holes | Differential | |
|---|---|---|---|---|---|---|
| 1 | — | |||||
| 2 | — | |||||
| 3 | — | |||||
| 4 | — | |||||
| 5 | — |
| Rounds Available | Differentials Used |
|---|---|
| 1 | Lowest 1 – 1.0 |
| 2–3 | Lowest 1 – 1.0 |
| 4–5 | Lowest 2 – 1.0 |
| 6 | Lowest 2 – 1.0 |
| 7–8 | Lowest 3 – 1.0 |
| 9 | Lowest 4 – 1.0 |
| 10 | Lowest 5 – 1.0 |
| 11–12 | Lowest 6 |
| 13–14 | Lowest 7 |
| 15–16 | Lowest 8 |
| 17 | Lowest 9 |
| 18 | Lowest 9 |
| 19 | Lowest 10 |
| 20 | Lowest 10 |
Course Rating: difficulty for scratch golfer. Slope: 55 (easiest) to 155 (hardest). Standard is 113.
The 113 in every golf differential is not arbitrary: it is the Slope Rating of a course of standard difficulty. Dean Knuth, the USGA's longtime handicapping director, explained that the average course's scores line had an observed slope of 1.13, and Slope was referenced to 113 to keep whole numbers. The system rolled out nationally in the United States from 1987. This page turns your scores, course ratings and slopes into differentials and an estimated index; it does not issue an official one.
Start with six rounds: 88 on a 71.2/128 course, 91 on 70.5/125, 85 on 72.0/113, 94 on 69.8/121, 87 on 71.5/130 and 90 on 72.4/135. The differentials come out at 14.8, 18.5, 13.0, 22.6, 13.5 and 14.7. With six rounds the page uses the lowest two, 13.0 and 13.47. Their average is 13.24, times 0.96 is 12.71, and the page shows 12.7.
The differential formula is (score − course rating) × 113 ÷ slope rating. For the first round that is (88 − 71.2) × 113 ÷ 128 = 16.8 × 113 ÷ 128 = 14.83. Course rating is the expected score of a scratch golfer, and slope runs from 55 to 155 in the usual range. Blank rows are ignored. A round marked 9 holes has its differential doubled.
How many differentials count: 1 to 3 rounds use the lowest 1; 4 to 6 use 2; then the count rises to n−4 for 7 to 8 rounds, n−5 for 9 to 11, n−6 for 12 to 14, n−7 for 15 to 16 and n−8 for 17 to 18. With 19 or 20 it is 10, and beyond 20 it is half the rounds. The average is multiplied by 0.96.
Be aware that this is a simplified estimate and differs from the official World Handicap System. The WHS averages the lowest 8 of your most recent 20 differentials with a minimum of 3 scores, makes adjustments for short records, caps hole scores and accounts for playing conditions, and has no 0.96 multiplier, which came from the older USGA method. Expect your official index to differ by a stroke or more.
No. An official index comes from a golf club or your national association, and uses the full WHS rules. Use this page to see how differentials work or to get a rough idea before posting scores.
On the scorecard or club website, listed separately for each set of tees and often separately for men and women. Using the wrong tee's numbers is the most common source of error.
The page doubles the differential. The row's own differential column does not show the doubling, but the index uses it. Official WHS handles 9-hole scores differently, so use 18-hole rounds where you can.
No. Only the most recent 20 count in the official system. This page uses half of whatever you enter once you pass 20, which would include older, less relevant scores.
The same 8 strokes over rating is 9.04 on a slope-100 course, 8.00 at 113 and 6.46 at 140. The harder the course, the less each stroke over the rating counts against you.
The table is shorthand. The line under your index tells you exactly how many differentials the calculation took.