Enter your recent scores with each course's rating and slope. We'll compute your Handicap Index using the World Handicap System, the same math your home club uses.
Add at least 3 rounds. For your most accurate index, post 20. Course Rating and Slope are printed on the scorecard or your course's tee sheet.
The World Handicap System (WHS) measures your demonstrated scoring ability rather than your average. It looks at your recent rounds, keeps only your best performances, and expresses them as a single portable number, your Handicap Index, that travels with you to any course in the world.
The first step is turning each round into a Score Differential. This adjusts your gross score for how hard the course and tees actually played, using the course's Course Rating and Slope Rating:
Once each round is a differential, your Handicap Index is the average of your lowest 8 differentials out of your most recent 20 rounds. Because only your best rounds count, the index reflects your potential, what you shoot when you play well, not your typical day.
Until you've posted 20 rounds, the system uses a sliding scale so newer golfers can still get a fair number. With fewer rounds, fewer differentials are averaged, and a small adjustment is applied:
| Rounds posted | Differentials used | Adjustment |
|---|---|---|
| 3 | Lowest 1 | −2.0 |
| 4 | Lowest 1 | −1.0 |
| 5 | Lowest 1 | 0 |
| 6 | Lowest 2 (average) | −1.0 |
| 7 – 8 | Lowest 2 | 0 |
| 9 – 11 | Lowest 3 | 0 |
| 12 – 14 | Lowest 4 | 0 |
| 15 – 16 | Lowest 5 | 0 |
| 17 – 18 | Lowest 6 | 0 |
| 19 | Lowest 7 | 0 |
| 20 | Lowest 8 | 0 |
This calculator applies that same table automatically. Add more rounds and watch the result tighten toward your true index.
You need a minimum of 3 rounds (54 holes) to establish a Handicap Index. It can be any combination of 18-hole and 9-hole rounds. Your index becomes more accurate and stable as you approach 20 posted rounds.
Your Handicap Index is portable and course-independent. Your Course Handicapis what you actually receive on a given day, the Index converted for the specific tees you're playing, using their Slope and Course Rating. This tool calculates your Index.
The maximum Handicap Index under the World Handicap System is 54.0, for both men and women. This keeps the game welcoming for beginners and higher-handicap players.
This calculator uses the official WHS formula so you can estimate your Index, but a formal, recognized handicap must be issued through an authorized golf association or club, which applies safeguards like the Playing Conditions Calculation and soft and hard caps.
For estimation purposes only. Ingrain is not affiliated with the USGA, R&A, or any national golf association. The World Handicap System and its formulas are administered by those bodies; an official Handicap Index must be obtained through an authorized provider.
Ingrain logs every round, tracks your Handicap Index over time, and builds each practice session around the shots costing you most.