About the Golf Handicap Calculator
A golf handicap measures the ability of a player so that golfers of different standards can compete fairly. This calculator follows the averaging method of the World Handicap System. For each round you enter the adjusted gross score, the course rating and the slope rating, and it works out the score differential. It then takes the best differentials from your most recent 20 rounds, applies the adjustment used when you have fewer than 20, and gives a Handicap Index to one decimal. Add a course's slope, rating and par to convert the index to a course handicap, the number of strokes you receive there.
Updated October 2026
How to use the Golf Handicap Calculator
- 1Type one round per line: score, course rating, slope, separated by spaces, with the newest round first.
- 2If you already know a score differential, type it alone on its line.
- 3Use at least 3 rounds. Only the latest 20 count.
- 4Read your Handicap Index and which differentials were used.
- 5Fill in the slope, course rating and par of a course to get your course handicap.
A worked example
Say you shot 88 on a course with a rating of 71.2 and a slope of 128. The differential is 113 divided by 128, times 16.8, which is 14.8. If your five best-known rounds give differentials of 14.8, 17.2, 15.6, 18.0 and 16.1, the best one is 14.8. With five rounds and no adjustment, your index is 14.8. As you add more rounds, the lowest differentials from the newest 20 take over.
Tips for entering rounds
- List the newest round first, because only the first 20 lines count.
- Use the course rating and slope for the tees you actually played.
- Use the adjusted gross score, with a net double bogey cap on each hole.
- Enter a single number on a line if you have a differential from an app or club record.
- Slope must be between 55 and 155.
Next steps
To join the official system, ask your local golf club or national association. Related tools on this site include the Average Calculator for checking the mean of your best differentials, the Percentage Calculator, and the Standard Deviation Calculator if you want to see how consistent your scores are. The Random Team Generator can help you pair players for a friendly competition.
Features
- Score differentials from score, rating and slope
- Best-of-20 rules for 3 to 20 rounds
- Handicap Index to one decimal, capped at 54.0
- Course handicap for any course
- Accepts ready-made differentials
- Shows exactly which rounds counted
- Runs in your browser
Frequently asked questions
How is a golf handicap calculated?
For each round, the score differential is 113 divided by the slope rating, times (adjusted gross score minus course rating). Your Handicap Index is the average of the lowest eight differentials out of your last 20 rounds. With fewer rounds, fewer differentials are used, with a small adjustment for 3 to 6 rounds.
How many rounds do I need?
You need at least three. With three rounds the best differential is used with an adjustment of minus 2.0, with four it is minus 1.0, and with five it is the best one with no adjustment. Six rounds use the best two with a minus 1.0 adjustment. From 20 rounds, the best eight count.
What are course rating and slope rating?
Course rating is the score a scratch golfer is expected to shoot on that course. Slope rating, from 55 to 155, shows how much harder the course is for a bogey golfer than for a scratch golfer, with 113 as the standard. Both are printed on the scorecard and are listed for each set of tees.
What is a course handicap?
It is the number of strokes you receive on a particular course and set of tees. It equals your Handicap Index times (slope divided by 113), plus (course rating minus par), rounded to a whole number. A higher slope means you receive more strokes.
What is adjusted gross score?
It is your total strokes with a cap on the maximum score at each hole, set at net double bogey, so one disastrous hole does not distort your handicap. Enter the adjusted figure here for the most accurate answer.
Is this my official handicap?
No. Official handicaps come from your national or regional golf association through your club. This calculator follows the standard averaging method but leaves out playing-conditions adjustments, the soft and hard caps and the combining of 9-hole rounds, so use it as an estimate.