Free WHS tool

Handicap Differential Calculator

One round in, one score differential out. Hole by hole mode caps every blow-up at net double bogey first, the step most calculators skip.

PCC is the playing conditions adjustment your association posts after the day. It is 0 on most days.

Score Differential

28.6

(113 ÷ 120) × (99 − 68.6 − 0) = 28.627, rounded to the nearest tenth.

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The Formula, From the Rules of Handicapping

Score Differential = (113 ÷ Slope) × (AGS − Course Rating − PCC)

AGS is the adjusted gross score: your real score after every hole is capped at its maximum. Course Rating is what a scratch golfer is expected to shoot from those tees. Slope scales the result to a course of standard difficulty, which is slope 113. PCC corrects for days when weather or setup made the course play harder or easier.

The differential is the number your Handicap Index is built from. The index averages your best 8 of your last 20, so one differential tells you whether a round will count. If it is lower than the eighth best in your record, it goes into the average. The golf handicap calculator does that part with up to 20 rounds.

Worked Examples From Official Sources

SourceAGSRatingSlopePCCDifferential
England Golf9968.6120028.6
USGA9571.5125021.2

England Golf: (99 − 68.6 − 0) × (113 ÷ 120) = 30.4 × 0.9417 = 28.63, posted as 28.6. USGA: (95 − 71.5) × 113 ÷ 125 = 21.24, posted as 21.2. Type either into the calculator and you get the same answer, which is how it was tested.

Net Double Bogey, Hole by Hole

Rule 3.1 caps each hole at net double bogey so one disaster does not wreck your index. The cap depends on how many strokes you get on that hole, and that depends on your Course Handicap and the hole's stroke index.

Course HandicapHoleStrokes receivedMax score
18Par 4, SI 714 + 2 + 1 = 7
24Par 5, SI 325 + 2 + 2 = 9
24Par 4, SI 1014 + 2 + 1 = 7
10Par 3, SI 1503 + 2 + 0 = 5
No index yetPar 3n/a3 + 5 = 8

A 24 gets two strokes on SI 1 to 6 and one on the rest. Plus handicaps work the other way: a +2 gives a stroke back on SI 17 and 18, so the max on those holes is par plus one. Hole by hole mode does all of this for you and shows which holes were capped in red.

Need your Course Handicap first? The course handicap calculator turns your index into it for any set of tees.

Sources

Frequently Asked Questions

What is the score differential formula?
Score Differential = (113 / Slope Rating) x (Adjusted Gross Score - Course Rating - PCC). It is Rule 5.1a of the Rules of Handicapping. The result is rounded to the nearest tenth, with .5 rounded up.
Is a handicap differential the same as a score differential?
Yes, in practice. Handicap differential was the name under the old USGA Handicap System. The World Handicap System, in use since 2020, calls it a Score Differential. The formula only changed by adding the PCC term.
What is net double bogey?
The most you can post on any hole: par plus two plus the strokes you receive on that hole. A 16 handicap gets one stroke on stroke index 1 to 16, so on a par 4 with SI 9 the max is 7. A golfer without a Handicap Index uses par plus five instead.
What is PCC?
The Playing Conditions Calculation. After each day the system compares scores posted at the course with what was expected and may adjust by -1 to +3. It is 0 most days. A +1 means the course played a shot harder, so one stroke comes off your differential.
How is a 9-hole differential worked out?
Since 2024, a 9-hole score is posted with the 9-hole Course Rating and Slope, then combined with an expected score for the other nine based on your Handicap Index (Rule 5.1b). That needs your index and the system's expected score table, so this calculator handles 18-hole rounds.

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