Golf Handicap Calculator (WHS Method)
An estimate of your handicap index by the World Handicap System method, from 18-hole scores with course and slope ratings: every score differential shown.
The score differential of each round, which of the most recent 20 count, the average of the lowest and the adjustment for short records, and the resulting handicap index estimate (to 0.1, at most 54.0).
Example: Eight rounds on four courses: the two lowest differentials, 14.3 and 14.9, average 14.6 — an index of 14.6; with three rounds it is the lowest minus 2.0.
The best
of your last 20.
How a score differential is worked out, how many of the last 20 count, how short records are adjusted, and why the official index can differ.
Score differential
Each round becomes (113 ÷ slope rating) × (adjusted gross score − course rating − playing conditions calculation), rounded to a tenth. The slope scales the score to a course of standard difficulty (113); the course rating is what a scratch golfer is expected to shoot.
The lowest of 20
From the most recent 20 differentials, the lowest 8 are averaged. With fewer scores the Rules of Handicapping use fewer: 1 of 3 to 5, 2 of 6 to 8, 3 of 9 to 11, and so on up to 7 of 19 — and records of 3, 4 and 6 scores are lowered by 2.0, 1.0 and 1.0. The result is rounded to a tenth and capped at 54.0.
Adjusted gross score
Enter each score after net double bogey — the most counted on a hole is par + 2 + any handicap strokes received there. The optional fourth figure is that day’s playing conditions calculation, from your association.
Why it is an estimate
Your official index is kept by your golf association and also applies the soft and hard caps against your low index, exceptional-score reductions and nine-hole scores, which are not modelled here. Handicap Index is a trademark of the USGA. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.
SOURCES
- Rules of Handicapping (World Handicap System), USGA and The R&A — Rules 5 and 6
Last reviewed 24 September 2026. How results are checked: How we verify.