World Handicap System (WHS) Calculator
Enter your round details to calculate your Score Differential.
How to Calculate Your Golf Handicap Index
In the modern World Handicap System (WHS), a golfer's handicap is determined by their Score Differential. This metric normalizes your score based on the difficulty of the course you played. It allows golfers of different abilities to compete fairly on any course globally.
The Mathematical Formula
To find your Score Differential for a specific round, use the following formula:
Score Differential = (Adjusted Gross Score – Course Rating) x (113 / Slope Rating)
Key Terms Explained
- Adjusted Gross Score: This is your total score after limiting any individual hole score to a "Net Double Bogey" for handicap purposes.
- Course Rating: A number (usually between 67 and 77) that represents the expected score for a "scratch golfer" (0 handicap) under normal conditions.
- Slope Rating: A value (ranging from 55 to 155) that indicates the relative difficulty of a course for a "bogey golfer" compared to a scratch golfer. The average slope is 113.
Example Calculation
If you shot an 88 on a course with a 70.5 rating and a 130 slope:
- 88 (Score) – 70.5 (Rating) = 17.5
- 113 / 130 (Slope) = 0.869
- 17.5 x 0.869 = 15.2 (Score Differential)
Establishing Your Handicap Index
Your actual Handicap Index is not based on just one round. According to the USGA and R&A:
| Number of Scores in Record | Differentials Used for Index |
|---|---|
| 5 to 6 rounds | Lowest 1 |
| 10 to 11 rounds | Lowest 3 |
| 15 to 16 rounds | Lowest 5 |
| 20 rounds | Lowest 8 (Average) |
Frequently Asked Questions
Why is 113 used in the formula?
113 is the "standard" slope rating established by the USGA. It represents a course of perfectly average difficulty. Dividing 113 by your course's slope adjusts your score to that baseline.
What is the maximum handicap?
Under the World Handicap System, the maximum Handicap Index for any golfer is 54.0, regardless of gender.