Tools
Score Differential Calculator
One round, one number. The Score Differential is the building block of every handicap: how good a round was once the difficulty of the tees is taken out of it.
Enter your round. The Score Differential updates as you type.
Fills the course rating and slope from our record where we hold one tee's full set. Or type them below.
Score Differential
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Fill in all three fields to see the differential for this round.
The formula
Score Differential = (Adjusted Gross Score − Course Rating) × 113 ÷ Slope Rating
The Course Rating is the score a scratch golfer is expected to shoot from a given set of tees; the Slope Rating (55 to 155, with 113 as the standard) measures how much harder the course plays for a bogey golfer than for that scratch golfer. Dividing by the Slope and multiplying by 113 puts every round on the same scale, so a 90 at a brutal track and an 85 at an easy one can be compared fairly. The result is rounded to one decimal place.
The formula in plain words
Take your adjusted gross score. Subtract the course rating of the tees you played, and subtract the playing conditions adjustment (a figure the handicap system applies on days when scores ran unusually high or low, and zero on most days; this calculator assumes zero). Multiply what is left by 113, then divide by the slope rating. In symbols: (113 ÷ Slope) × (Adjusted Gross Score − Course Rating − PCC).
A worked example
A round of 95 at Torrey Pines South Course in La Jolla, California, from the Black tees, where our record holds a course rating of 78.8 and a slope of 148, on a normal day (PCC 0): 95 minus 78.8 is 16.2; 16.2 times 113 is 1,830.6; divided by 148 that is 12.37, which rounds to a Score Differential of 12.4. The same 95 on a standard course (rating 72.0, slope 113) would be 23.0, which is how much harder Torrey Pines South plays.
How to read the result
A lower Score Differential is a better round. On a standard course (rating 72.0, slope 113) the differential is simply your score minus 72. Collect several of these and the best of them, averaged, become your Handicap Index. The “Adjusted” Gross Score caps any disaster hole at a net double bogey for handicap purposes; for most rounds it equals your real score.