This golf handicap calculator computes a World Handicap System (WHS) Handicap Index from your recent rounds: it converts each score to a differential (using course rating and slope) and applies the official best-scores table for however many rounds you enter.
How the WHS Builds an Index
Each round becomes a score differential = (113 ÷ slope) × (adjusted gross score − course rating) — normalizing every course to a standard difficulty. Your index is the average of your best few differentials from the last 20 rounds (8 of 20 at full record), per the official table this calculator implements. It measures your demonstrated ability on good days, deliberately — a handicap is potential, not average. Part of our Sports Calculators collection.
Worked Example (Verified)
- Twenty rounds at rating 71.2 / slope 128 (defaults, scores 82–89): differentials run 9.5–15.7; the best 8 (9.5, 9.5, 10.4, 10.4, 10.4, 11.3, 11.3, 11.3) average 10.53 → Handicap Index ≈ 10.5
- Single-differential check: an 85 shot at 71.2/128 → (113/128) × 13.8 = 12.2
- Nine rounds only: best 3 count — a thin record makes a volatile index, by design it stabilizes as rounds 12–20 accumulate
- Course handicap at a harder track (slope 140, rating 72.5, par 72): 10.5 × (140/113) + (72.5 − 72) ≈ 13.5 → about 14 strokes
The Parts This Estimator Omits (On Purpose)
- Adjusted gross: official differentials cap each hole at net double bogey — one blow-up hole shouldn’t define you. Enter adjusted scores if your card has disasters.
- Soft/hard caps against your Low Index of the past year, exceptional-score reductions (−1/−2), and daily PCC (playing conditions) adjustments — association software applies these; a web estimator cannot see them.
- 9-hole scores combine pairwise into 18-hole differentials in the official system.
Related Tools
- Bowling Handicap Calculator — equalization, alley edition
- Average Calculator — your plain scoring average (not a handicap)
- Sports Calculators — the full collection
Frequently Asked Questions
How is a golf handicap calculated under the WHS?
Convert each score to a differential: (113 ÷ slope) × (score − course rating). Average the lowest differentials per the table (8 of 20 for a full record; fewer for shorter records, with adjustments for 3–6 rounds). The result, truncated to one decimal, is your Handicap Index.
What is a score differential?
Your score re-expressed on a standard-difficulty course. Shooting 85 at a 71.2/128 course gives (113/128) × 13.8 = 12.2 — you played “12.2 over standard scratch” that day, portable to any other course’s math.
Handicap Index vs course handicap — what’s the difference?
The Index is yours and travels. The course handicap converts it for today’s course: Index × (slope/113) + (course rating − par). Harder course → more strokes received; the worked example turns a 10.5 index into ~14 strokes at a 140-slope track.
Why does the WHS use my best rounds, not my average?
By philosophy: a handicap represents demonstrated potential so that a player having a normal-good day competes fairly. Averaging all rounds would gift strokes to inconsistency and penalize steady players. The best-8-of-20 window keeps it current — old glories expire off the back of the record.
How many rounds do I need for a handicap?
Three 18-hole rounds (or 54 holes in combination) earn an initial index under the WHS, computed from your single best differential minus a 2.0 adjustment. It firms up progressively until the full 20-round record is established.
Is this golf handicap calculator free?
Yes — free, instant, no sign-up. It estimates; official indexes come from your golf association.