Golf Handicap Index Calculator
Calculate a World Handicap System score differential from your round, estimate your handicap index, and convert it to a course handicap.
How it works
Score differential = (113 ÷ slope) × (adjusted gross score − course rating − PCC) · Course handicap = index × (slope ÷ 113)
The World Handicap System converts every round into a score differential that strips out how hard and how sloped the course played, so scores from different courses become comparable. Your official Handicap Index is the average of the best 8 of your most recent 20 differentials — a single round only estimates it, which is why this shows the differential plainly. To play a specific course you convert the index into a course handicap using that tee’s slope.
Worked example
A 92 on a course rated 71.4 with slope 128: (113 ÷ 128) × (92 − 71.4 − 0) = 0.8828 × 20.6 = 18.2 differential. Across a full record, low differentials like this feed the index.
Sources: World Handicap System
Frequently asked questions
Why isn’t one round my handicap?
The index uses the best 8 of your last 20 score differentials to reward your demonstrated ability, not a single good or bad day. One round gives a differential, which is one ingredient.
What is slope rating?
Slope measures how much harder a course plays for a bogey golfer than for a scratch golfer, on a scale where 113 is average. Higher slope inflates differentials less per stroke over rating.
What is an adjusted gross score?
Your score after applying the net double bogey cap to each hole — the most you can post is a par-plus-2 plus any handicap strokes — which stops one disaster hole from wrecking your differential.
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This calculator is for educational purposes. Double-check important results before acting on them.