Quick answer
A score differential = (adjusted gross score − course rating) × 113 ÷ slope, and the Handicap Index averages the lowest differentials. Scores of 85, 90 and 88 on courses rated 71.2, 71.2 and 70.5 with slopes 125, 125 and 122 give differentials of 12.5, 17.0 and 16.2; the lowest one, adjusted by −2.0, gives an index of 10.5.
Enter 3 to 20 adjusted scores with their course and slope ratings. The calculator returns the Handicap Index and the number of scores counted. Use this golf handicap calculator to check your own figures.
Related tools: Winning Percentage Calculator: Winning percentage from wins, losses and ties. Batting Strike Rate Calculator: Cricket batting strike rate. Batting Average Calculator: Baseball batting average from hits and at-bats.
How to use the Golf Handicap Calculator
- Type adjusted gross scores, for example 85, 90, 88.
- Type course rating for each score, for example 71.2, 71.2, 70.5.
- Type slope rating for each score, for example 125, 125, 122.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Adjusted gross scores | Text, such as 85, 90, 88 | — |
| Course rating for each score | Text, such as 71.2, 71.2, 70.5 | — |
| Slope rating for each score | Text, such as 125, 125, 122 | — |
Formula and method
Formula
differential = (score − course rating) × 113 ÷ slope; index = average of the lowest N differentials (+ adjustment) by number of scores
IEEE-754 double precision; shown to the decimals indicated.
Follows World Handicap System Rule 5.2 for 3 to 20 scores; it ignores the playing-conditions adjustment and the soft and hard caps, so an official index may differ. Informational estimate, not medical advice. Talk to a qualified health professional about your own situation.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Adjusted gross scores = 85, 90, 88; Course rating for each score = 71.2, 71.2, 70.5; Slope rating for each score = 125, 125, 122.
| Result | Value |
|---|---|
| Handicap Index | 10.5 |
| Scores counted | 1 lowest of 3 |
Example 2
Inputs: Adjusted gross scores = 88, 91, 85, 94, 87, 90, 86, 92, 89, 95, 84, 93, 88, 90, 87, 91, 85, 96, 89, 92; Course rating for each score = 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0, 72.0; Slope rating for each score = 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113.
| Result | Value |
|---|---|
| Handicap Index | 14.3 |
| Scores counted | 8 lowest of 20 |
Example 3
Inputs: Adjusted gross scores = 95, 99, 102, 97, 101, 96; Course rating for each score = 69.5, 69.5, 69.5, 69.5, 69.5, 69.5; Slope rating for each score = 118, 118, 118, 118, 118, 118.
| Result | Value |
|---|---|
| Handicap Index | 23.9 |
| Scores counted | 2 lowest of 6 |
The first line is the headline result (handicap Index). Below it the golf Handicap Calculator lists scores counted, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
Why 113
113 is the slope rating of a course of standard difficulty. A course with a higher slope is harder, so the same score gives a lower differential. This adjusts scores to a common scale.
World Handicap System
With 20 scores the best 8 are averaged. With fewer, fewer differentials count and an adjustment applies: for 3 scores, the lowest one minus 2.0. The result is an index and the course handicap for a given course adds slope and rating.
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Adjusted gross scores: entering "85, 90" shows "Enter at least 3 numbers." beside that field and no result.
- Course rating for each score: entering "71, 71" shows "Enter one course rating per score." beside that field and no result.
Choosing between the Golf Handicap Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Winning Percentage Calculator](/fitness/winning-percentage/) | wins, losses and ties count as | Winning percentage |
| [Batting Strike Rate Calculator](/fitness/batting-strike-rate/) | runs scored and balls faced | Strike rate |
| [Batting Average Calculator](/fitness/batting-average-calculator/) | hits and at-bats | Batting average |
| [Basketball Shooting Percentage Calculator](/fitness/basketball-shooting-percentage-calculator/) | field goals made and field goals attempted | Field goal % |
| [Football Goal Difference Calculator](/fitness/football-goal-difference-calculator/) | goals for and goals against | Goal difference |
Background: fitness estimates
Fitness formulas are estimates whose accuracy depends on the input. One-rep-max formulas such as Epley and Brzycki give different answers, and predictions from hard sets of a few repetitions are better than from sets of ten or more. Age-based maximum heart rate formulas can be off by 10 to 30 beats a minute for an individual; Tanaka's 208 − 0.7 × age is generally preferred to 220 − age but is still an estimate.
Pace models built from a race result assume a maximal effort and work best for distances from about 5 km to the marathon. Use the output as a guide, not a prescription.
Assumptions and limitations
- Enter between 3 and 20 scores
- Not a diagnosis
Estimates from formulas describe averages. They are not a training or medical prescription; check with a qualified professional before changing your exercise or diet.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for adjusted gross scores and course rating for each score to confirm this.
Frequently asked questions
What is a course rating?
The expected score of a scratch golfer.
What is slope rating?
A measure of difficulty for bogey golfers.
How many scores do I need?
At least 3 scores; with 3 the index uses the lowest differential minus 2.0, and more scores use more differentials.
What does the Golf Handicap Calculator calculate?
World Handicap System index from your recent scores. It returns Handicap Index and Scores counted.
What formula does the Golf Handicap Calculator use?
differential = (score − course rating) × 113 ÷ slope; index = average of the lowest N differentials (+ adjustment) by number of scores. Follows World Handicap System Rule 5.2 for 3 to 20 scores; it ignores the playing-conditions adjustment and the soft and hard caps, so an official index may differ.
What do I need to enter in the golf Handicap Calculator?
You enter Adjusted gross scores, Course rating for each score and Slope rating for each score.
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. Enter between 3 and 20 scores.
What are the limits of this calculator?
Enter between 3 and 20 scores. Not a diagnosis.
What is an example of a golf Handicap result?
With adjusted gross scores 85, 90, 88, course rating for each score 71.2, 71.2, 70.5 and slope rating for each score 125, 125, 122, the handicap Index is 10.5.
Where does the method come from?
The method follows: R&A and USGA, Rules of Handicapping (World Handicap System), Rule 5.2.
Can I rely on this calculator for a decision?
Estimates from formulas describe averages. They are not a training or medical prescription; check with a qualified professional before changing your exercise or diet. For this calculator in particular: Enter between 3 and 20 scores.
Related calculators
- Winning Percentage Calculator — Winning percentage from wins, losses and ties.
- Batting Strike Rate Calculator — Cricket batting strike rate.
- Batting Average Calculator — Baseball batting average from hits and at-bats.
- Basketball Shooting Percentage Calculator — Field-goal, effective field-goal and three-point percentages.
- Football Goal Difference Calculator — Goals scored minus goals conceded.
- On-Base Percentage Calculator — Baseball on-base percentage.
Sources
- R&A and USGA, Rules of Handicapping (World Handicap System), Rule 5.2
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.