⛳ Golf Handicap Differential Calculator
Enter a round's adjusted gross score, the course rating, and the slope to get its score differential — the per-round figure that builds your handicap index.
🧮 Calculate a Differential
Why the Differential Matters
A raw score doesn't say much on its own — an 85 on a brutal championship layout is a very different round from an 85 on a gentle par-70. The score differential fixes that by folding in the course rating and slope, restating every round on the same 113-slope scale.
Collect a differential for each round and the best of them average into your handicap index. This single-round tool is handy for checking one score, comparing two courses, or sanity-testing a number before you post it.
❓ Frequently Asked Questions
What is a score differential?
It's a single round expressed on a common scale: (adjusted gross score − course rating) × 113 ÷ slope. Multiplying by 113 — the standard slope — and dividing by the course's slope normalises the round so differentials from different courses and tees can be compared and averaged into a handicap index.
Why 113?
113 is the slope rating of a course of standard relative difficulty in the World Handicap System. Using it as the reference means a round played on a tougher (higher slope) course produces a proportionally lower differential for the same gross score.
Can a differential be negative?
Yes. If you shoot below the course rating, the differential is negative — a sign of an excellent round relative to the tees you played.