See the “HCP Index” next to your name on the Deemples app. Wonder how this number is calculated from the scores you have submitted on the app. Here we’ll show you how to calculate a USGA Golf Handicap Index (HCP Index).
Formula to Calculate Golf Handicap Index
Handicap Index = Average of your qualified Handicap Differentials * 0.96
2 questions here:
- How do you calculate Handicap Differentials?
- Which Handicap Differentials qualify for Handicap Index calculations?
1. Formula to calculate Handicap Differential per game
Handicap Differential = (Adjusted Gross Score – Course Rating) * 113 / Slope Rating
More questions here:
- What is Adjusted Gross Score (AGS)?
- What is Course Rating?
- What is Slope Rating?
What is Adjusted Gross Score
Gross Score = Sum of your scores for each hole.
Adjusted Gross Score, however, takes into account Equitable Stroke Control (ESC) where the maximum allowable score per hole for handicapping purposes is dependent on your course handicap. See the following table:
| Course Handicap | Maximum Allowable Score Per Hole |
| <10 | Double Bogey (+2) |
| 10-19 | 7 |
| 20-29 | 8 |
| 30-39 | 9 |
| >39 | 10 |
Course Handicap = Slope rating / 113 * Handicap Index
Course Rating and Slope Rating
Course Rating and Slope Rating are numbers that are available on the scorecard that show a difficulty of a golf course from a specific tee box in relation to another tee box of the same golf course or any other golf course using the same USGA rating system.
They usually look like this:
| Blue Tee (Men) | White Tee (Men) | Red Tee (Women) | |
| Course Rating | 71.7 | 68.9 | 71.4 |
| Slope Rating | 132 | 127 | 127 |
- Course Rating – the higher the number, the more difficult the golf course
- Slope Rating – the higher the number, the more difficult the golf course
If a woman plays off the White Tee box, they wouldn’t be using the Men’s course and slope rating numbers for the white tee, but the women’s rating instead. If these ratings are not available on the scorecard, check with the golf course.
Going back to how a Course Handicap is calculated, and let’s say for this example, we’re playing off the men’s blue tee box with a 13.9 HCP Index:
Course Handicap = 132 / 113 * 13.9
= 16.237 or 16 (rounding to the nearest whole number)
So since my Course Handicap is 16 from the blue tees at Kinrara Golf Club, for my Adjusted Gross Score, based on the table above, the maximum allowable score per hole for handicapping purposes, would be 7.
My Gross Score for the game is the sum of all my scores for each hole. Let’s say for this game my score for each hole was:
| Hole | Gross Score | Adjusted Gross Score |
| 1 | 5 | 5 |
| 2 | 9 | 7 |
| 3 | 5 | 5 |
| 4 | 5 | 5 |
| 5 | 6 | 6 |
| 6 | 5 | 5 |
| 7 | 7 | 7 |
| 8 | 4 | 4 |
| 9 | 4 | 4 |
| 10 | 5 | 5 |
| 11 | 5 | 5 |
| 12 | 4 | 4 |
| 13 | 6 | 6 |
| 14 | 9 | 7 |
| 15 | 7 | 7 |
| 16 | 4 | 4 |
| 17 | 4 | 4 |
| 18 | 6 | 6 |
| 100 | 96 |
As you can see on hole 2 and hole 14, I had a 9, which both are 2 over the maximum allowable score for handicapping purposes. Therefore, my Adjusted Gross Score for this game is 96 for handicapping purposes, whilst my Gross Score is still 100 for competition purposes.
Net Score = Gross Score – Course Handicap
In competition, my net score would be 100 – 16 = 84.
Back to Handicap Differentials
Handicap Differential = (Adjusted Gross Score – Course Rating) * 113 / Slope Rating
Now that we know what Adjusted Gross Score, Course Rating, and Slope Ratings are, for this example we use the numbers above.
The Handicap Differential for this game
= (96 – 71.7) * 113 / 132
= 20.8 (round to 1 decimal point from 20.802)
2. Which Handicap Differentials qualify for Handicap Index Calculations
Now that we know how to calculate the handicap differential for each game, it’s important to know which of the handicap differentials qualify for Handicap Index calculations.
Depending on the number of handicap differentials from games you have posted results for, the number of handicap differentials you use is different:
| Number of games posted | Number of Differentials to be used |
| 5-6 | Lowest 1 |
| 7-8 | Lowest 2 |
| 9-10 | Lowest 3 |
| 11-12 | Lowest 4 |
| 13-14 | Lowest 5 |
| 15-16 | Lowest 6 |
| 17 | Lowest 7 |
| 18 | Lowest 8 |
| 19 | Lowest 9 |
| 20 | Lowest 10 |
Let’s say for this example, we have played 7 games, and have 7 differentials to use. Including the 20.8 we had above, we also have:
| Games Posted | Handicap Differentials |
| 1 | 20.8 |
| 2 | 20.3 |
| 3 | 18.9 |
| 4 | 17.1 |
| 5 | 15.9 |
| 6 | 14.8 |
| 7 | 18.9 |
Based on 7 available differentials, and based on the table above that, the number of differentials used for handicap index calculation would be the lowest 2 = 14.8 and 15.9.
So based on:
Handicap Index = Average of your qualified Handicap Differentials * 0.96
My new Handicap Index
= (14.8 + 15.9)/2 * 0.96
= 14.736
Do not round this number, but remove the digits up to the tenth decimal.
So 14.736 becomes a handicap index of 14.7.
If the number ended up being 14.787, DO NOT round handicap index to 14.8, but again, remove digits to the tenth decimal, which will still give you a handicap index of 14.7.
DO NOT ROUND, but DROP digits to the nearest tenth decimal.
Migrating to World Handicap System (WHS)
Starting in 2020, some countries in the world are on a 2-year plan to migrate from their existing handicap systems to the World Handicap System (WHS). This effort is to standardize golf handicaps around the world, so everyone can compete on a level playing field.
For this to happen, there are a few variables that have to be standardized, which mostly include the difficulty levels of the golf courses. 2 measurements used a) Course Rating and b) Slope Rating, would have to be implemented for golf courses all around the world. With the USGA-rated golf courses already having course and slope ratings implemented, which is more than 50% of the world, the rest will follow suit.
USGA Golf Handicap Index Calculator
Link: https://www.usga.org/course-handicap-calculator.html
Deemples Handicap System
This transition to WHS will take 2 years, until the end of 2021. For the time being Deemples will continue using the USGA method since it requires way fewer variables. Only 1) Adjusted Gross Score 2) Course Rating, and 3) Slope Rating for it to be accurately calculated.
We’ll do another update again when we switch over to WHS, which might be later down the road. Meanwhile, we kinda agree with: https://www.golfdigest.com/story/voices-the-flaw-in-the-new-world-handicap-system-dean-knuth
If you want to know about ‘Golf Handicap Score Submission’ on Deemples, Click here.
Summary of How to Calculate USGA Golf Handicap Index
There you go! Now you know how to calculate your Golf Handicap Index. I know it looks very overwhelming, but with practice & experience, for sure you will be able to handle it. Regardless, we hope you keep on golfing and improving.
Speaking of golfing, if you can’t seem to find anyone to golf with, then check out the Deemples App.
Deemples is a golf app that makes sure you never golf alone. It’s super simple to use; All you do is create/join a game and boom! You now have golf partners to play with.
Download Deemples today and enjoy golfing!
