USGA Handicap Formula | Group Golf Handicap Tracker

A Handicap Index is the service mark used to indicate a measurement of a player’s potential ability on a course of standard difficulty. Potential ability is measured by a player’s best scores, and is expressed as a number taken to one decimal place. These scores are identified by calculating the handicap differential for each score. The USGA Handicap Index is calculated by taking 96 percent of the average of the best handicap differentials, and applying Section 10-3 for golfers with two or more eligible Tournament Scores.

How to Determine Handicap Differentials

A handicap differential is computed from four elements: adjusted gross score, USGA Course Rating, USGA Slope Rating and 113 (the Slope Rating of a course of standard difficulty). To determine the handicap differential, subtract the USGA Course Rating from the adjusted gross score; multiply the difference by 113; then divide the resulting number by the USGA Slope Rating. Round the final number to the nearest tenth.Handicap Differential =
(Adjusted Gross Score – USGA Course Rating) x 113 / USGA Slope Rating
Adjusted Gross Score using equitable stroke control

Course Handicap	Maximum Number Posted on Any Hole
9 or less	Double Bogey
10 through 19	7
20 through 29	8
30 through 39	9
40 or more	10

a. Plus Handicap Differential

When the adjusted gross score is higher than the USGA Course Rating, the handicap differential is a positive number. Following is an example for determining a differential using an adjusted gross score of 95 made on a course with a USGA Course Rating of 71.5 and a USGA Slope Rating of 125:

Adjusted Gross Score – USGA Course Rating:		95 – 71.5 = 23.5
Difference x Standard Slope:		23.5 x 113 = 2655.5
Result / USGA Slope Rating:		2655.5 / 125 = 21.24
Handicap Differential (rounded):		21.2

b. Minus Handicap Differential

When the adjusted gross score is lower than the USGA Course Rating, the handicap differential is a negative number. Following is an example for determining a differential using an adjusted gross score of 69 made on a course with a USGA Course Rating of 71.5 and a USGA Slope Rating of 125:

Adjusted Gross Score – USGA Course Rating:		69 – 71.5 = -2.5
Difference x Standard Slope:		-2.5 x 113 = -282.5
Result / USGA Slope Rating:		-282.5 / 125 = -2.26
Handicap Differential (rounded):		-2.3

USGA Handicap Index Formula

The USGA Handicap Index Formula is based on the best handicap differentials in a player’s scoring record. If a player’s scoring record contains 20 or more scores, the best 10 handicap differentials of the most recent 20 scores are used to calculate the USGA Handicap Index. The percentage of scores used in a scoring record decreases from the maximum of the best 50 percent as the number of scores in the scoring record decreases. If the scoring record contains 9 or 10 scores, only the best three scores (30 to 33 percent) in the scoring record will be used. Thus, the accuracy of a player’s Handicap Index is directly proportional to the number of acceptable scores posted. A USGA Handicap Index shall not be issued to a player who has returned fewer than five acceptable scores. The following procedures illustrate how authorized golf associations and golf clubs calculate a player’s Handicap Index.The procedure for calculating Handicap Indexes is as follows:

Use the table below to determine the number of handicap differentials to use;

Number of Acceptable Scores	Differentials To Be Used
5 or 6	Lowest 1
7 or 8	Lowest 2
9 or 10	Lowest 3
11 or 12	Lowest 4
13 or 14	Lowest 5
15 or 16	Lowest 6
17	Lowest 7
18	Lowest 8
19	Lowest 9
20	Lowest 10

Determine handicap differentials;
Average the handicap differentials being used;
Multiply the average by .96; *
Delete all numbers after the tenths’ digit. Do not round off to the nearest tenth.Example 1: Fewer than 20 scores (11 scores available).

Total of lowest 4 handicap differentials:
104.1

Average (104.1 / 4):
26.025

Multiply average by .96:
24.984

Delete digits after tenths:
24.9

USGA Handicap Index:
24.9

* Bonus for Excellence is the incentive that is built into the USGA Handicap System for players to improve their golf games. It is the term used to describe the small percentage below perfect equity that is used to calculate Handicap Indexes (96%). As his Handicap Index improves (gets lower), the player has a slightly better chance of placing high or winning a handicap event.

Example 2: Twenty Scores available. The following is a sample scoring record of a player with 20 scores.

Total of 10 lowest differentials:
154.8

Average (154.8 / 10):
15.48

Average multiplied by .96:
14.861

Delete all digits after tenths:
14.8

USGA Handicap Index:
14.8
Apply Section 10-3 for golfers with two or more eligible tournament scores.

Date	USGA Adjusted Score	USGA Course Rating	Slope Rating	Handicap Differential
3/21/97	90	70.1	116	19.4
3/12/97	91	70.1	116	20.4
2/24/97	94	72.3	123	19.9
2/20/97	*88	70.1	116	17.4
1/18/97	89	70.1	116	18.4
1/17/97	*90	72.3	123	16.3
1/16/97	*91	72.3	123	17.2
12/12/96	91	70.1	116	20.4
12/10/96	91	70.1	116	20.4
11/8/96	86	68.7	105	18.6
11/4/96	90	70.1	116	19.4
11/1/96	*92	72.3	123	18.1
10/24/96	*85	68.0	107	18.0
10/16/96	*78	68.7	105	10.0
10/12/96	*82	70.1	116	11.6
10/2/96	*84	70.1	116	13.5
9/14/96	94	72.3	123	19.9
9/5/96	93	72.3	123	19.0
9/4/96	*89	72.3	123	15.3
9/1/96	*88	70.1	116	17.4
* 10 scores with lowest handicap differentials

USGA. 2012. USGA HANDICAP FORMULA. [ONLINE] Available at: http://usga.org/Rule-Books/Handicap-System-Manual/Rule-10/. [Accessed 08 September 15].

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