Calculate Handicap Index from recent rounds for fair course-to-course score comparison.
A golf handicap calculator standardizes scoring ability across courses of different difficulty by using score differentials.
Under the World Handicap System approach, the best recent differentials are averaged and adjusted to produce Handicap Index.
Use valid adjusted gross scores with course data.
Input rating for each round played.
Input slope value associated with each tee set.
Apply slope-normalized differential formula.
Use top subset per WHS rules.
Multiply by 0.96 where applicable to index method.
Differential = (113 / Slope) x (Adjusted Gross Score - Course Rating); Handicap Index ~= average(best differentials) x 0.96
Differentials normalize score performance for course difficulty, then best rounds are averaged into a portable handicap index.
Differential = (113/128) x (88 - 72.4) = 13.78
Round differential: 13.8
HI = 12.4 x 0.96 = 11.90
Handicap Index: 11.9
Course handicap ≈ 11.9 x (132/113)
Course handicap ≈ 13.9 before local rounding/rules