Golf Handicap Calculator
Track rounds and compute your World Handicap System index and course handicap — with the counted-rounds rule people find counterintuitive.
Rating and slope are printed on the scorecard for the tees you played. Rounds save in this browser.
The score you post is not the score you shot
Under the World Handicap System every hole is capped at net double bogey — par, plus two, plus any strokes you get on that hole. A blow-up hole is written down in full on the card and posted as the cap, and posting the raw number instead inflates your index. Work out the cap for a hole here:
How the World Handicap System works
Every round becomes a Score Differential — (113 ÷ slope) × (score − rating) — which converts your day into a common scale regardless of course difficulty. Your Index is the average of your best differentials from the last 20 rounds: the best 8 once you have 20, with a sliding scale (and a small adjustment) for fewer. Your Course Handicap then converts that index back to strokes on a specific set of tees. The math here follows the published WHS tables and is unit-tested, including the small-sample tiers and the rule that strokes allocated across 18 holes sum exactly to your course handicap. Official handicaps require posting through an authorized club — this is for practice, leagues and settling arguments.
How to use
- Enter each round with the course rating and slope.
- Read your handicap index once you have enough rounds.
- Convert to a course handicap for the tees you play.
- Post every round, not just the good ones.
Frequently asked questions
How is a handicap index calculated?
From the best 8 score differentials of your most recent 20 rounds, averaged. Only the best eight count, which is why a handicap represents your potential rather than your average — most golfers score worse than their handicap most of the time, and that is by design.
What is the difference between index and course handicap?
The index is portable and course-independent. The course handicap converts it for the specific course and tees using the slope rating, and then adjusts for the difference between course rating and par. The same index gives different strokes at different courses, which is the entire point of the system.
What is slope rating?
A measure of how much harder a course plays for a bogey golfer relative to a scratch golfer. The standard value is 113, which is why it appears in the conversion. A high slope means the course punishes weaker players disproportionately, so they receive more strokes there.
Should I post bad rounds?
Yes, always, and not posting them is the commonest form of handicap manipulation. Since only your best eight differentials count, a bad round has limited effect on the index anyway — the reason people omit them is usually pride rather than arithmetic.
What is net double bogey?
The maximum score you can post on a hole for handicap purposes: par plus two plus any strokes you receive there. It stops one disastrous hole distorting your index, and it means the score you post for handicap can be lower than the score you actually took.
Why did my handicap change without playing?
Because the World Handicap System applies a playing conditions calculation and reviews indexes periodically, and because your 20-round window moves as rounds age out. A good round dropping out of the window can raise your index without you touching a club.
🔒 This tool runs entirely in your browser. Nothing you enter is uploaded, logged, or stored.