How to calculate a golf handicap
Your handicap is calculated based on the your most recent 20 rounds of golf. Depending on how many scores you have, a subset of those scores will be used to
determine your handicap. If you only have 5-6 scores, your best score is used. If you have all 20 then your best 10 are used. And between 1 and 10 if you have between 7 and 19 scores.
Here is an exact breakdown of how many rounds are used:
If you have less than or equal to 6 rounds: best 1 score
If you have 7 or 8 rounds: best 2 scores
If you have 9 or 10 rounds: best 3 scores
If you have 11 or 12 rounds: best 4 scores
If you have 13 or 14 rounds: best 5 scores
If you have 15 or 16 rounds: best 6 scores
If you have 17 rounds: best 7 scores
If you have 18 rounds: best 8 scores
If you have 19 rounds: best 9 scores
If you have 20 rounds: best 10 scores
If you have more than 20 scores, your 20 most recent ones are
used for handicap calculation.
Once the number of rounds to use is determined. For each round used you calculate the round differential. Which is calculated by the following formual:
((score - rating) * 113) / slope
The average of the differentials is then calculated and the result is multiplied by .96
The result is your handicap.