The World Handicap System's core formula — Score Differential = (Adjusted Gross Score − Course Rating) × 113 ÷ Slope Rating — is publicly documented and used at every affiliated club worldwide. What trips up casual calculators is the second part: with fewer than 20 rounds posted, an official table determines how many of your lowest differentials count and what adjustment applies.
Score differential calculator, the WHS formula itself
Enter your score, the course rating, and the slope rating for each round, and this calculator computes the Score Differential exactly per the WHS formula — normalizing for how difficult that specific course and tees played.
How to calculate golf handicap with fewer than 20 rounds
With 3 to 19 rounds entered, this calculator follows the official reduced-count table (for example, 9–11 rounds uses your lowest 3 with no adjustment; 3 rounds uses your lowest 1 with a −2.0 adjustment) rather than just averaging everything you've entered.
Handicap index calculator, not a certified one
This is an unofficial estimate for personal tracking. A certified USGA/R&A Handicap Index has to be issued through a licensed club or association, and this tool doesn't apply the "exceptional score reduction" rule, which needs your existing official handicap to calculate in the first place.
