How This Calculator Works
For each round, the calculator computes a Score Differential: (Adjusted Gross Score − Course Rating) × 113 ÷ Slope Rating. Your Handicap Index is then the average of your lowest differentials, multiplied by 0.96. How many differentials get used depends on how many rounds you've entered, per the official WHS table below.
| 3 rounds | Lowest 1 differential, minus 2.0 |
| 4–6 rounds | Average of lowest 2, minus 1.0 |
| 7–8 rounds | Average of lowest 2 |
| 9–11 rounds | Average of lowest 3 |
| 12–14 rounds | Average of lowest 4 |
| 15–16 rounds | Average of lowest 5 |
| 17–18 rounds | Average of lowest 6 |
| 19 rounds | Average of lowest 7 |
| 20 rounds | Average of lowest 8 |
A Note on Accuracy
This tool implements the core WHS calculation but omits the Playing Conditions Calculation (PCC), a day-specific weather/course-condition adjustment the USGA applies in real handicap tracking. For your official Handicap Index, post scores through your national golf association's app or GHIN.
Want the full explanation of how handicaps work? See our guide: What a Handicap Actually Measures.