Handicap Index Estimator

Enter your last 5–20 adjusted gross scores and course/slope ratings.

Score 1 (adjusted gross)

Course rating

Slope rating

Score 2

Course rating 2

Slope 2

Score differential 1 —

Score differential 2 —

Average best differential —

Estimated handicap index —

Differential = (113 / slope) × (score − course rating). WHS uses the best 8 of your last 20 differentials. This simplified version averages the differentials entered.

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How Golf Handicap Index Works

The World Handicap System (WHS) calculates your handicap index from your best score differentials. A differential measures how you performed relative to the course difficulty.

With 20 rounds, the WHS uses the average of your best 8 differentials. With fewer rounds, it uses fewer differentials. This calculator provides an estimate — for an official handicap, register with your golf association.

Golf handicap index (World Handicap System, effective 2020) is calculated as the average of the best 8 of your most recent 20 Score Differentials, multiplied by 0.96. Score Differential = (Adjusted Gross Score − Course Rating) × (113 / Slope Rating). Course Rating and Slope Rating are printed on every scorecard.

Example: score 92 on a course with Rating 70.5 and Slope 125. Adjusted Gross Score = 92 (apply equitable stroke control if any hole exceeds your maximum). Score Differential = (92 − 70.5) × (113/125) = 21.5 × 0.904 = 19.4. Accumulate 20 differentials, use the best 8, average them, multiply by 0.96 = Handicap Index.

Course Handicap converts your index to strokes at a specific course: Course Handicap = Handicap Index × (Slope/113) + (Course Rating − Par). A 15.0 index at a course with Slope 130 and par 72, Rating 72.5: 15.0 × (130/113) + (72.5 − 72) = 17.3 + 0.5 = 17.8 → round to 18. You receive 18 strokes over par.

The WHS soft cap limits rapid upward movement: if your index rises more than 3.0 above your Low Handicap Index from the previous 12 months, increases above that threshold are reduced by 50%. This prevents inflated handicaps from poor performance without penalizing genuine deterioration.