About this Golf Handicap
A Golf Handicap allows players of different skill levels to compete fairly. Your 'Handicap Index' is an average of your best recent differentials. This tool calculates the Differential for a single round, which is the core number used to update your index.
Who this calculator is for
- Golfers tracking progress from round to round.
- League players and scorekeepers comparing course difficulty fairly.
- Anyone who needs the differential for a specific round.
When to use it
- Calculate a handicap differential for one round.
- Compare scores across courses with different ratings and slopes.
- Monitor whether recent rounds are trending better or worse.
How to use this calculator
- Enter your Gross Score (total strokes).
- Enter the Course Rating (from the scorecard).
- Enter the Slope Rating (from the scorecard).
- The result is your Handicap Differential.
Key assumptions
- Gross score, course rating, and slope rating are entered from the same round.
- The formula follows the standard USGA differential method.
- This calculator does not produce an official handicap index by itself.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
The USGA formula is:
Differential = (Score - Course Rating) × 113 / Slope Rating
113 represents the slope of a standard difficulty course.
Inputs explained
Course Rating
The expected score for a 'scratch' golfer (0 handicap). Usually between 67 and 77.
Slope Rating
A measure of difficulty for a 'bogey' golfer relative to a scratch golfer. Standard is 113; difficult courses go up to 155.
Understanding your results
This number is not your final handicap. It is the performance rating of *that specific round*. To find your Handicap Index, average the lowest 8 differentials of your last 20 rounds.
Example scenarios
Good Round
Score 80. Rating 70. Slope 113. Diff = (80-70)*1 = 10.0.
Hard Course
Score 85. Rating 72. Slope 135. Diff = (85-72)*113/135 = 10.9.
Key Features
- USGA Formula
- Standard Slope (113)
- Instant Differential
Tips & Best Practices
- Always adjust your gross score for 'Net Double Bogey' (max hole score) before calculating, per World Handicap System rules.
- A high Slope Rating means the course is significantly harder for high-handicappers than for pros.
Glossary of Terms
- Scratch Golfer
- A player with a handicap of 0.
- Bogey Golfer
- A player with a handicap of roughly 20 (averages about 90 on a standard course).