Differential versus handicap index
A full handicap index is based on multiple differentials and official rules. This calculator only gives the differential for one round, which is useful for checking the core arithmetic.
Example
With an adjusted gross score of 88, course rating of 72.1 and slope of 125, the differential is (88 - 72.1) x 113 / 125, or about 14.4 before any official index processing.
Common mistakes
Use adjusted gross score, not necessarily the raw scorecard total. Also make sure the course rating and slope match the tee set played.
Limitations
This is not an official handicap index calculator. Official systems can include score differentials from multiple rounds, playing conditions adjustments, rounding rules and governing-body procedures.
Last reviewed: 2026-05-17