Golf Handicap Index Calculator

About this calculator

The World Handicap System (WHS) converts a round's adjusted gross score into a score differential using the formula (adjusted gross score − course rating) × 113 ÷ slope rating, which normalizes the raw score for how hard that specific course played that day — course rating reflects the expected score of a scratch golfer, and slope rating (ranging 55-155, with 113 as standard difficulty) reflects how much harder the course plays for a bogey golfer relative to a scratch golfer. A golfer's handicap index is then derived by averaging the best differentials from their most recent rounds.

Golfers use their handicap index to get course handicaps at any course they play — even one they've never seen before — because the index travels with the golfer while the conversion to a specific course happens locally using that course's own rating and slope, which is what makes it possible for golfers of very different skill levels to compete fairly against each other.

This calculator takes your adjusted gross score, the course rating and the slope rating for a single round, and returns that round's score differential — the building block your official handicap index is calculated from.