Work out your Handicap Index.
Enter a gross score, the course rating and the slope rating for each round. This runs the World Handicap System maths: a score differential per round, then the average of your best few. It is the same engine the SHANKED app uses on a real card, so the number here is the number there.
Your rounds
Most recent first. Course rating and slope are printed on the scorecard and on the tee box. Three rounds is the minimum the system will work from.
| Score | Course rating | Slope |
|---|
Enter three rounds to see an index.
How a golf handicap is actually calculated
Every round you play produces one number, called a score differential. It answers a narrow question: how good was that round, on that course, from those tees, compared with what a scratch golfer would be expected to shoot.
The 113 is the slope rating of a course of average difficulty, so dividing by the slope of the course you actually played scales your round back to that standard. Course rating is the expected score for a scratch golfer, and it is rarely a round number: 71.2 or 73.8, not 72.
Then the best few, averaged
Your Handicap Index is the average of your best differentials from your last twenty rounds, and how many count depends on how many rounds you have. With a full record of twenty, the best eight count. With five rounds, only the best one does, and an adjustment is applied on top. Fewer than three rounds and there is no index at all, because the World Handicap System will not stand behind a number built on less than 54 holes.
This is why one bad round barely moves your handicap and one very good round can. The average is of your best, not of everything.
What this calculator does not do
Two parts of the full system need information a web form does not have, and inventing them would give you a number that is not your index. Both are stated rather than quietly skipped:
- Soft cap and hard cap. WHS limits how fast an index can rise against your lowest index of the previous 365 days. That needs a year of history, so it is not applied here. The app applies it, because the app has the history.
- Net Double Bogey. Before the differential is worked out, each hole is capped at net double bogey. That needs your score hole by hole and the stroke index of the course. This calculator uses the gross score you type, which is the right answer when you have not had a blow-up hole and slightly generous when you have.
A number from this page is a good estimate of where you stand. It is not an official handicap, and neither is the one in the app. An official Handicap Index comes from a club affiliated to your national body, who hold your record.
Nine-hole rounds
Nine holes count towards a handicap under WHS, but they are combined rather than doubled, and the shots are allocated over the nine you actually played. This calculator takes eighteen-hole rounds only. The app handles nines properly, including two nines played as one round.
If any of this is new, the golf handicap guide walks through the whole system, including the parts this page leaves out.
Or let the app do it every time you finish
SHANKED works your handicap out from the card as you save it, keeps the full twenty round record, and applies the caps this page cannot. Free to start, and nobody needs a card.
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