How we worked it out
Updated as you change the numbers.
- Score differential = (113 ÷ slope) × (score − course rating), rounded to one decimal.
- Average the lowest differentials (8 of 20, fewer when you have fewer rounds) and apply any adjustment.
- Course handicap = index × slope ÷ 113 + (course rating − par).
Method and assumptions
This follows the World Handicap System’s calculation, which took effect in 2020. Your official index also applies the playing-conditions calculation, exceptional-score reductions and caps on rapid increases, so treat this as an estimate. Use adjusted gross scores (with net double bogey as the maximum per hole).
Questions
How many scores do I need for a handicap?
At least 54 holes (three 18-hole rounds). With 20 or more, the best 8 of the last 20 differentials are averaged.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.