In golf, the term "handicap index" is used to describe an individual player's best potential for scoring in relation to par.

To properly calculate your handicap index, you need to play a minimum of 5 rounds of 18-hole golf, and no more than 20 rounds. We will take our gross score for each of these rounds as well as some basic info for the golf course we are playing on, and run it through the magic formula established by the USGA.

The 2 things you will need to know are the Course Rating and Slope Rating of the course in question. you can find both of these numbers on the course's scorecard.



The USGA Course Rating is a number representing the course difficulty to an expert (scratch golfer), and is issued by the USGA based on factors such as yardage and obstacles.

The USGA Slope Rating represents the difficulty relative to a bogey golfer, or someone who's handicap is around 17 - 22.

Both of these numbers will also vary depending on which tee you are playing at. a higher number represents a more difficult course. The slope rating is always higher than the course rating not just because bogey players are less skilled, but because they also tend to perform much worse as the course difficulty increases. Scratch golfers on the other hand, tend to remain consistently at par regardless of the difficulty; which is why the 2 separate numbers are used.

Before we begin, a quick note about scoring:

To keep a proper score while you are playing ranked games, you need to follow the ESC (Equitable Stroke Control) guidelines. This simply puts a limit on the maximum number of strokes you can record for a hole, and is based on your course handicap. Since you can't figure your course handicap until you know your handicap index, we will use the default value of 36.4. With that in mind, the maximum score you can record per hole is 9

Course Index	Maximum # Of Strokes
9 or less	double bogey
10 to 19	7
20 to 29	8
30 to 40	9
40 and above	10

Step 1: Calculate the handicap differentials for each round.
Handicap Differential = ( (strokes-CourseRating) * 113 ) / SlopeRating
The number 113 represents the average slope rating.

Step 2: Find out your lowest usable differentials.
Depending on how many rounds of 18-hole golf you are testing (5-20), you will be allowed to discard a certain number of bad rounds. Remember the goal is to discover your best potential, so we need to use only the best scores.

Here is a chart you can use to determine how many handicap differentials to use:



Step 3: Find the average of the lowest handicap differentials
Once you've found out how many differentials to use, finding the average is easy. Just add them up and divide the result by the total number of differentials you used.

Step 4: Multiply the result by .96
The number .96 lowers the value just a bit, and actually helps you improve your game by reducing your handicap.

Step 5: Drop all decimal places except for the "tenths" place.
Do not round up or down, just chop off the decimals after the tenths place, and leave it as is.

The resulting number is your handicap index as the USGA calculates it!

Like I mentioned before, if you are an avid golfer who plays regularly at a club, you probably already have this stuff taken care of through the club's in-house system. The above information is just provided to shed some light on the process, and give casual golfers an opportunity to find out their handicap index on their own.

If you don't want to fuss with all of the math, just use one of the free handicap index calculators online

Once you have your USGA handicap index, you can use it to determine your Course Handicap for any course that uses the USGA system. Simply multiply your handicap index by the course's slope rating, then divide the answer by 113. Round to the nearest whole number, and you now have the course handicap value that you can use when playing handicap rounds of golf!