How to Calculate a USGA Handicap

Calculate the handicap differential for each round by using the USGA Course Ration and Slope Rating for the courses played. That formula is HCP Dif = (Score - Course Rating) x 113 / Slope Rating. For example, the score is 75, the course rating is 71.2 and the slope is 130, so the formula will look like (75 - 71.2) x 113/130. Repeat this step differential for each round.

Figure out how many differentials one must use. Use only the lowest differentials according to how many rounds you've entered. For five to six rounds, use the lowest differential; for seven to eight, use the two lowest; nine to 10, the three lowest; and 11 to 12, the four lowest differentials. For 13 to 14 rounds use five differentials; 15 to 16, use 6. For 17 to 20, increase one differential per round used.

Find the average of the differentials used to get the handicap index. For example, if you use the five lowest, add those together and divide it by five. Then multiple the answer by 0.96, and the digits after the tenths are dropped in the result. The formula reads like this: HCP index = (sum of differentials/number of differentials) x 0.96.

Use the handicap index to find the course handicap. You do this because course difficulty varies, and your handicap on one course may not be the same as your handicap on another.

To find the course handicap, use your handicap index and the Slope Rating of the Tees Played divided by the average slope rating of 113. That formula is Course Handicap=(Your HCP Index) x (Slope Rating of Tees Played)/113. For example, your handicap index is 16.7 and tee box slope is 127. So 16.7 x 127/113 = 19, meaning the course played was harder than the average course and made the course handicap higher than the handicap index.