How Your Handicap Index Is Calculated
World Handicap System (WHS)
MyGolfIndex uses the official World Handicap System formula — the same method used by golf associations worldwide.
Step 1 — Score Differential
Each round produces a Score Differential using this formula:
Differential = (Adjusted Gross Score − Course Rating) × (113 ÷ Slope Rating)
Step 2 — Adjusted Gross Score
Before calculating the differential, your gross score is capped at Par + 36 (equivalent to a maximum of double bogey on every hole). This is a simplified Equitable Stroke Control (ESC) adjustment.
Step 3 — Handicap Index
Your index is calculated from the best differentials in your most recent 20 rounds, using the WHS lookup table below:
| Rounds Posted | Differentials Used | Adjustment |
|---|---|---|
| 3 | Lowest 1 | −2.0 |
| 4 | Lowest 1 | −1.0 |
| 5 | Lowest 1 | None |
| 6 | Lowest 2 | −1.0 |
| 7–8 | Lowest 2 | None |
| 9–11 | Lowest 3 | None |
| 12–14 | Lowest 4 | None |
| 15–16 | Lowest 5 | None |
| 17–18 | Lowest 6 | None |
| 19 | Lowest 7 | None |
| 20 | Lowest 8 | None |
Maximum Index
The WHS caps the handicap index at 54.0 for all golfers.
Note: Handicap indexes on MyGolfIndex are calculated using WHS methodology
but are not certified USGA handicaps. For an official USGA handicap,
visit usga.org.