Golf Handicap Differential Calculator
Work out a single round’s score differential — the building block of your Handicap Index. Free and instant.
Score Differential
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Enter your score, course rating, and slope.
What a score differential is
Every round in the World Handicap System produces one score differential, which normalizes your score for how hard the course played:
Score Differential = (113 ÷ Slope) × (Adjusted Score − Course Rating)
Example: an adjusted 88 on a course rated 70.4 with a slope of 128: (113 ÷ 128) × (88 − 70.4) = 0.883 × 17.6 ≈ 15.5. Collect ~20 of these and your Handicap Index is the average of the lowest 8.
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Frequently asked questions
- What is a score differential?
- A score differential measures how well you played one round relative to the course’s difficulty: (113 ÷ Slope) × (Adjusted Score − Course Rating). It normalizes your score so rounds on different courses are comparable.
- How many differentials make up a Handicap Index?
- Your index uses the lowest differentials from your most recent 20 rounds — the lowest 8 once you have 20. With fewer rounds a reduced table decides how many count.
- What score should I enter?
- Use your adjusted gross score — your score with a per-hole maximum (net double bogey) applied — for a differential that matches how the WHS treats the round.
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