Enter your rounds — course rating, slope rating, and score — to calculate your Handicap Index.
How to Use the Golf Handicap Calculator
Add a row for each round with its Course Rating, Slope Rating, and Adjusted Gross Score, then read the differential calculated per row and the Handicap Index totaled below. Remove a row with the × button if you entered one by mistake.
The World Handicap System (WHS) took effect in 2020, unifying what had been a patchwork of separate national systems — the USGA's in the US, CONGU's in Great Britain and Ireland, and others across Europe, Australia, and South Africa — into one global standard. Before that, a handicap earned on one system didn't translate cleanly to another, which mattered more than it might sound for golfers who traveled or competed internationally.
Course Rating vs. Slope Rating
Course Rating is the expected score for a scratch golfer (handicap zero) playing that course under normal conditions — usually a number close to par. Slope Rating measures how much harder the course plays for a bogey golfer relative to a scratch golfer, on a scale where 113 is defined as "standard" difficulty — which is exactly why 113 shows up as a constant in the differential formula rather than some other number.
Score Differential = (113 ÷ Slope Rating) × (Adjusted Gross Score − Course Rating)The official Handicap Index averages the best 8 of a golfer's most recent 20 rounds, then applies a more complex reduced-count table for golfers with fewer than 20 rounds on record. This calculator simplifies that part: with 8 or more rounds entered, it averages the best 8 differentials; with fewer than 8, it averages everything entered. Both paths get multiplied by 0.96, per the WHS formula. It's a simplification of the official low-round-count table, not an exact reproduction — good enough to track your own trend, not a substitute for an official handicap from your golf association.