Golf Handicap Differential Calculator
Calculate your handicap differential for a single round, based on your score, course rating, and slope rating.
What a handicap differential measures
A handicap differential adjusts your raw score for the specific difficulty of the course you played, using its course rating (the expected score for a scratch golfer) and slope rating (a measure of relative difficulty for a bogey golfer versus a scratch golfer). This allows scores from different courses to be fairly compared.
A lower differential indicates a stronger relative performance — shooting the same raw score on a harder course (higher slope) produces a lower, better differential than shooting that same score on an easier course.
How this fits into an official handicap index
An official USGA-style Handicap Index isn't based on a single round — it's typically calculated from an average of your best several differentials out of your most recent 20 rounds, following specific rules maintained by golf's governing bodies. This calculator computes the differential for a single round, which is the building block of that larger calculation.
The standard slope rating for an 'average' difficulty course is 113 — courses with a slope above 113 are considered more difficult than average for a bogey golfer relative to a scratch golfer, and courses below 113 are considered easier.
Frequently asked questions
Is this the same as my official USGA Handicap Index?
No — an official Handicap Index is calculated from an average of your best differentials across your most recent rounds, following specific governing body rules. This calculator computes the differential for a single round, which is a building block of that calculation.
What does a slope rating of 113 mean?
113 represents a course of 'average' relative difficulty. Courses with a higher slope are considered more challenging for a bogey golfer relative to a scratch golfer, and courses below 113 are considered comparatively easier.