What is a Golf Handicap?
A golf handicap measures a player's potential ability, allowing golfers of different skill levels to compete fairly. The core building block is the handicap differential, which adjusts your score for the difficulty of the course and tees you played. This calculator computes the differential for a single round and gives an estimated handicap index.
How to Use This Calculator
Enter three numbers from your round: your adjusted gross score (total strokes), the course rating (the expected score for a scratch golfer, e.g. 72.0), and the slope rating (a measure of difficulty for bogey golfers, between 55 and 155, where 113 is average). The calculator returns the differential and an estimated index.
The Formula Explained
The differential is calculated as $$\text{Differential} = (\text{Score} - \text{Course Rating}) \times \frac{113}{\text{Slope}}$$ The 113 represents the standard (average) slope rating, so the calculation normalizes every course to the same difficulty scale. A full handicap index is the average of your best recent differentials multiplied by 0.96; here we apply 0.96 to a single differential to give a quick estimate.
Worked Example
Suppose you shoot a 90 on a course with a rating of 72.0 and a slope of 125. The differential $$= (90 - 72.0) \times \frac{113}{125} = 18 \times \frac{113}{125} = \frac{2034}{125} = \mathbf{16.272}$$ The estimated index $$= 16.272 \times 0.96 = \mathbf{15.6}$$
FAQ
Is this an official handicap? No — an official handicap index averages your best differentials over many rounds. This tool estimates from a single round.
What is slope rating? It reflects the relative difficulty of a course for a bogey golfer compared with a scratch golfer; 113 is the standard.
Why multiply by 0.96? The 0.96 "bonus for excellence" factor is part of the traditional handicap formula and slightly lowers the index.
