Golf Index Calculator

Handicap Index —

Rounds used: —
Differentials counted: —
Adjustment: —
Lowest differential: —
Average of all differentials: —

A golf Handicap Index under the World Handicap System is the average of your lowest 8 score differentials from your most recent 20 rounds. Each differential is (113 ÷ Slope) × (score − Course Rating − PCC). An 85 on a 71.2 / 128 course gives 12.2. With fewer than 20 rounds, a table sets how many count and a small deduction.

About this tool

Golfers keeping their own records, club secretaries checking a player's figure, and new players posting their first cards all need the same arithmetic: turn each scorecard into a differential, then average the right number of the lowest ones. Here you paste rounds straight from your notes, one per line, as score, Course Rating and Slope Rating. The table shows each round's differential and marks the ones that count, so you can see which cards are carrying your index. Between 3 and 19 rounds the tool applies the Rule 5.2 table, including the 2.0 and 1.0 deductions for very short records. It does not apply the soft cap or hard cap, which depend on your Low Handicap Index over the past year, nor exceptional-score reductions, so an official figure from your association can differ.

How to use it

List your rounds
Type or paste one round per line, oldest first: adjusted gross score, Course Rating, Slope Rating. You can also open a .txt or .csv file.
Set PCC if needed
Use the − and + buttons for the playing conditions calculation; leave it at 0 unless your association published another value.
Read the index
The Handicap Index appears at the top, with the number of differentials counted and any adjustment applied.
Check the table
Each round's differential is listed, and the ones used in the average are marked Yes.

Examples

A full record of 20 rounds

Rounds, oldest first: 80 72 113 81 72 113 82 72 113 83 72 113 84 72 113 85 72 113 86 72 113 87 72 113 88 72 113 89 72 113 90 72 113 91 72 113 92 72 113 93 72 113 94 72 113 95 72 113 96 72 113 97 72 113 98 72 113 99 72 113
Playing conditions calculation (PCC): 0

Result Handicap Index: 11.5
Rounds used: 20
Differentials counted: 8
Adjustment: 0.0
Lowest differential: 8.0
Average of all differentials: 17.5

Differential per round = (113 ÷ Slope) × (Score − Course Rating − PCC), PCC = 0
20 rounds on record, so WHS uses the lowest 8
Lowest differentials: 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0
Average = 92.0 ÷ 8 = 11.5
Handicap Index = 11.5

Scores of 80 to 99 on a 72.0 / 113 course give differentials of 8.0 to 27.0. The best eight, 8.0 to 15.0, average 11.5.

A new golfer with three cards

Rounds, oldest first: 85 71.2 128 90 72 113 95 72 113
Playing conditions calculation (PCC): 0

Result Handicap Index: 10.2
Rounds used: 3
Differentials counted: 1
Adjustment: -2.0
Lowest differential: 12.2
Average of all differentials: 17.7

Differential per round = (113 ÷ Slope) × (Score − Course Rating − PCC), PCC = 0
3 rounds on record, so WHS uses the lowest 1 and adjusts by -2.0
Lowest differentials: 12.2
Average = 12.2 ÷ 1 = 12.2
Handicap Index = 10.2

The 85 on a 71.2 / 128 course is the lowest differential at 12.2. With only three scores WHS subtracts 2.0, so the starting index is 10.2.

A scratch-plus player

Rounds, oldest first: 68 72 113 70 72 113 69 72 113 71 72 113 70 72 113
Playing conditions calculation (PCC): 0

Result Handicap Index: +4.0
Rounds used: 5
Differentials counted: 1
Adjustment: 0.0
Lowest differential: -4.0
Average of all differentials: -2.4

Differential per round = (113 ÷ Slope) × (Score − Course Rating − PCC), PCC = 0
5 rounds on record, so WHS uses the lowest 1
Lowest differentials: -4.0
Average = -4.0 ÷ 1 = -4
Handicap Index = +4.0

Five rounds under the 72.0 rating: the lowest differential is -4.0, shown the WHS way as a plus handicap of +4.0.

How it is calculated

Differential = (113 ÷ Slope) × (AGS − CR − PCC); Index = mean of lowest k differentials + adjustment

AGS: Adjusted gross score, after net double bogey limits
CR: Course Rating of the tees played
Slope: Slope Rating of the tees, 55 to 155; 113 is neutral
PCC: Playing conditions calculation, −1 to +3
k: How many differentials count: 1 for 3–5 rounds, rising to 8 for 20

Each differential is rounded to one decimal. Only the most recent 20 rounds are kept. Rule 5.2 of the Rules of Handicapping sets k and the adjustment: 3 rounds use the lowest one minus 2.0, 4 rounds the lowest minus 1.0, 6 rounds the average of two minus 1.0, and from 9 rounds upward k grows by one roughly every two or three cards until 20 rounds use 8. The result is rounded to a tenth and capped at 54.0. A negative result is written as a plus handicap.

When not to use it

For the official index that governs competitions, which your national association calculates with caps applied.
For nine-hole rounds, which WHS converts to 18-hole differentials with an expected-score method not modelled here.
To find strokes received on a given course, which is a Course Handicap and needs a separate conversion.

Common mistakes

Entering the raw gross score instead of the score capped at net double bogey on each hole.
Listing rounds newest first, so the wrong 20 are kept once you have more than 20.
Swapping Course Rating and Slope Rating on a line; the rating is near par, the slope is usually above 100.
Using par instead of the Course Rating for the tees actually played.

Frequently asked questions

Why are only 8 of my 20 rounds counted?

WHS is built to reflect your demonstrated potential rather than your average day. Taking the lowest 8 of 20 differentials gives a figure that a golfer playing well can reach, which is what makes net competitions between players of different standards fair.

What happens with fewer than 20 rounds?

Rule 5.2 sets a sliding scale. With 3 rounds the lowest differential minus 2.0 is used; with 4, the lowest minus 1.0; with 5, the lowest alone; with 6, the average of the lowest two minus 1.0. From there the count rises until 20 rounds use 8 with no deduction.

What does a Slope Rating of 113 mean?

113 is the Slope of a course of standard relative difficulty. At 113 the factor 113 ÷ Slope equals 1, so a differential is simply score minus Course Rating. Harder courses for bogey golfers have higher slopes, which shrink the differential for the same score.

Why is my result shown with a plus sign?

If your lowest differentials are below zero you play better than scratch. Golf writes such an index as a plus figure, so a computed −2.3 is shown as +2.3, meaning strokes are added to your score in net play.

What is PCC and when does it change?

The playing conditions calculation is a daily adjustment of −1 to +3 that the handicap system applies when scores across a course that day are far above or below expectation, for example in strong wind. Your association's posted score record shows it; most days it is 0.

Why might my club show a different index?

Official systems also apply the soft cap and hard cap, which limit how fast an index can rise above your lowest index of the past 12 months, plus reductions after exceptional scores. They also use nine-hole score conversions. None of those are applied here.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 10). Golf Index Calculator. Tools Directory. Retrieved October 26, 2026, from https://tools.milunir.com/sports/golf-bowling-and-racquet-sports/golf-index-calculator/

MLA

Tools Directory Editorial Team. “Golf Index Calculator.” Tools Directory, 10 Oct. 2026, https://tools.milunir.com/sports/golf-bowling-and-racquet-sports/golf-index-calculator/. Accessed 26 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Golf Index Calculator.” Tools Directory. Last modified October 10, 2026. Accessed October 26, 2026. https://tools.milunir.com/sports/golf-bowling-and-racquet-sports/golf-index-calculator/.

Link

<a href="https://tools.milunir.com/sports/golf-bowling-and-racquet-sports/golf-index-calculator/">Golf Index Calculator – Tools Directory</a>