About this tool
The Golf Handicap Calculator turns a set of rounds into a World Handicap System (WHS) style Handicap Index and, for a course you plan to play, a Course Handicap. Add as many rounds as you like — score, course rating and slope for each — and it recalculates instantly in your browser.
For every round it computes a Score Differential = (113 / Slope Rating) × (Adjusted Gross Score − Course Rating). Your most recent 20 rounds count toward the index. From those it averages a set number of your best (lowest) differentials — the full WHS uses the best 8 of 20, with a smaller count and a small adjustment when you have fewer rounds (for example the best 1 of 3 with a −2.0 adjustment) — then multiplies the average by 0.96 and caps the result at 54.0. Your Course Handicap is Index × (Slope ÷ 113), and if you enter the course rating and par it adds (Rating − Par) as the WHS formula does, rounded to a whole number.
Enter your Adjusted Gross Scores (net double bogey capped, as WHS requires) for the most accurate figure. This is an estimate for practice and planning: an official Handicap Index must be issued by an authorized golf association that also applies playing-conditions and safeguard adjustments.