The golf handicap calculation is something that most golfers never have to worry about. If you carry an official USGA Handicap Index, the calculation is performed for you by other people (or, far more likely, by a computer). You can also get an unofficial estimate of your handicap by using a golf handicap calculator.

But you want the nuts and bolts of the handicap formula, don’t you? You want to know the math behind figuring handicaps. OK, you asked for it, you got it.

## What You’ll Need for the Handicap Formula

What numbers do you have to have in order to perform the handicap index calculation? The formula requires the following:

Have all that? OK, we’re ready to get into the math of the handicap formula.

## Step 1 In Handicap Formula: Calculate the Differentials

Using your adjusted gross scores, the course ratings, and slope ratings, Step 1 is calculating the handicap differential for each round entered using this formula:

(Score – Course Rating) x 113 / Slope Rating

For example, let’s say your score is 85, the course rating 72.2, the slope 131. The formula would be:

(85 – 72.2) x 113 / 131 = 11.04

The sum of that calculation is called your “handicap differential.” This differential is calculated for each round entered (minimum of five, maximum of 20).

(Note: The number 113 is a constant and represents the slope rating of a golf course of average difficulty.)

## Step 2: Determine How Many Differentials To Use

Not every differential that results from Step 1 will be used in the next step. If only five rounds are entered, only the lowest of your five differentials will be used in the following step. If 20 rounds are entered, only the 10 lowest differentials are used. Use this chart to determine how many differentials to use in your handicap calculation.