Score Differential Calculator
One round, three numbers, one differential. Exactly what your handicap app computes under the hood.
The formula
differential = (score − course rating) × 113 ÷ slope
113 is the "average" slope baseline. The ratio 113 / slope scales your round as if it were played on an average-difficulty course. Subtracting course rating removes the baseline difficulty, leaving just "how well you played."
FAQ
What is a score differential in golf?
A score differential expresses how well you played a round relative to the difficulty of the course. It's the building block of your handicap index — you can't compute a handicap without differentials.
What is the USGA differential formula?
(Adjusted Gross Score − Course Rating) × 113 ÷ Slope Rating. 113 is the baseline slope for an "average" course; the ratio adjusts your score to that baseline.
What's a good differential?
A scratch golfer's differentials cluster near 0. A 10-handicap averages differentials around 10-12. A 20-handicap around 20-24. Lower is better.
Why does slope matter?
Two rounds of 85 — one on a tough 140-slope course, one on an easy 110-slope course — represent very different play quality. Slope normalizes them.
Want to compute a full handicap from many rounds? Use the Handicap Index Calculator — it applies the WHS best-8-of-20 method automatically.