Golf Handicap Calculator: Handicap Index and Course Handicap (WHS)
Your Handicap Index is the average of the 8 lowest Score Differentials from your most recent 20 rounds. Each Score Differential is (113 ÷ Slope Rating) × (Adjusted Gross Score − Course Rating). Enter your rounds below and the calculator does both steps, including the adjustments that apply when you have fewer than 20 scores.
Calculate your Handicap Index
Enter the adjusted gross score you shot plus the Course Rating and Slope Rating of the tees you played — both are printed on the scorecard. Three rounds is the minimum needed to establish a Handicap Index; 20 gives the full calculation.
Convert it to a Course Handicap
A Course Handicap is the number of strokes you receive on one specific course and set of tees: Handicap Index × (Slope Rating ÷ 113) + (Course Rating − par).
Course Rating Slope Rating Par
What this calculator does not do. It sets the daily Playing Conditions Calculation (PCC) to zero, and it does not apply the two safeguards built into the World Handicap System — the exceptional score reduction (triggered by a score 7.0 strokes or better than your Handicap Index) and the cap on upward movement (triggered when the 8-of-20 calculation runs 3.0 or more above your Low Handicap Index from the previous 365 days). Both need your full scoring history. An official Handicap Index can only be issued by an authorized golf club or association.
How a Handicap Index is calculated
The World Handicap System works in two steps. First, every round becomes a Score Differential that measures the round against the difficulty of the course played:
Score Differential = (113 ÷ Slope Rating) × (Adjusted Gross Score − Course Rating − PCC adjustment)
The 113 is the Slope Rating of a course of standard difficulty, which is what makes the result portable: an 85 on a hard course and an 80 on an easy one can produce the same differential. Second, those differentials are averaged — but only the best of them. With a full record of 20 scores, the 8 lowest are averaged. With fewer, this table applies:
| Score Differentials in your record | Differentials used | Adjustment |
|---|---|---|
| 3 | Lowest 1 | -2.0 |
| 4 | Lowest 1 | -1.0 |
| 5 | Lowest 1 | 0 |
| 6 | Average of lowest 2 | -1.0 |
| 7 or 8 | Average of lowest 2 | 0 |
| 9 to 11 | Average of lowest 3 | 0 |
| 12 to 14 | Average of lowest 4 | 0 |
| 15 or 16 | Average of lowest 5 | 0 |
| 17 or 18 | Average of lowest 6 | 0 |
| 19 | Average of lowest 7 | 0 |
| 20 | Average of lowest 8 | 0 |
Source: the Rules of Handicapping, Rule 5. A minimum of three acceptable 18-hole scores is required before a Handicap Index exists at all.
Course Handicap by Slope Rating
A Handicap Index is not the number of strokes you play off. That is your Course Handicap, and it changes with the tees. The table below shows the conversion across the full Slope Rating range (55 to 155, with 113 as the neutral point), with Course Rating equal to par so the slope effect is isolated.
| Handicap Index | 55 | 75 | 95 | 113 * | 125 | 135 | 145 | 155 |
|---|---|---|---|---|---|---|---|---|
| 0.0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 5.0 | 2 | 3 | 4 | 5 | 6 | 6 | 6 | 7 |
| 10.0 | 5 | 7 | 8 | 10 | 11 | 12 | 13 | 14 |
| 15.0 | 7 | 10 | 13 | 15 | 17 | 18 | 19 | 21 |
| 18.0 | 9 | 12 | 15 | 18 | 20 | 22 | 23 | 25 |
| 20.0 | 10 | 13 | 17 | 20 | 22 | 24 | 26 | 27 |
| 25.0 | 12 | 17 | 21 | 25 | 28 | 30 | 32 | 34 |
| 30.0 | 15 | 20 | 25 | 30 | 33 | 36 | 38 | 41 |
| 36.0 | 18 | 24 | 30 | 36 | 40 | 43 | 46 | 49 |
* Slope Rating 113 is the standard baseline, where Course Handicap equals Handicap Index. Course Handicap is rounded to the nearest whole number only when net double bogey adjustments are applied — otherwise the unrounded value is kept and used to work out a Playing Handicap (Course Handicap × the handicap allowance for the format being played).
What is my handicap if I shoot 90?
There is no exact answer from a single score, because a Handicap Index comes from the best 8 of your last 20 rounds rather than your average round. But if you consistently shoot a given score on a course of standard difficulty (Course Rating 72.0, Slope Rating 113, par 72), your index will settle in a predictable band. The USGA notes that a player shoots 2 to 5 strokes above their handicap in most rounds, which is the range used here.
| If you usually shoot | Score Differential for that round | Handicap Index typically lands around |
|---|---|---|
| 75 | 3.0 | 0.0 – 1.0 · see a 1 handicap |
| 80 | 8.0 | 3.0 – 6.0 · see a 5 handicap |
| 85 | 13.0 | 8.0 – 11.0 · see a 10 handicap |
| 90 | 18.0 | 13.0 – 16.0 · see a 15 handicap |
| 95 | 23.0 | 18.0 – 21.0 · see a 20 handicap |
| 100 | 28.0 | 23.0 – 26.0 · see a 25 handicap |
| 105 | 33.0 | 28.0 – 31.0 · see a 30 handicap |
| 110 | 38.0 | 33.0 – 36.0 · see a 35 handicap |
| 115 | 43.0 | 38.0 – 41.0 |
On a harder or easier course the same score produces a different differential — that is the whole point of the Slope Rating. Use the calculator above with your real Course Rating and Slope Rating rather than reading a number off this table.
Golf handicap explained → What each Handicap Index actually shoots, level by level, and how the same index turns into different strokes on different tees.
Frequently asked questions
How do you calculate a golf handicap?
Calculate a Score Differential for each round with the formula (113 / Slope Rating) x (Adjusted Gross Score - Course Rating - PCC adjustment). Once you have 20 scores in your record, your Handicap Index is the average of the 8 lowest Score Differentials from those 20 rounds. With fewer than 20 scores a smaller number of differentials is used, sometimes with an adjustment.
How many rounds do you need for a handicap?
You need a minimum of 3 acceptable 18-hole scores to establish a Handicap Index. With 3 scores your lowest Score Differential is used with a 2.0 adjustment; the calculation reaches its full form of "average of the lowest 8" at 20 scores.
What is the highest golf handicap you can have?
The maximum Handicap Index that can be issued to a player is 54.0 (Rule 5.3 of the Rules of Handicapping). A Committee running a competition may set a lower limit for entry, but 54.0 is the ceiling of the system itself. This calculator caps its result there.
What is the difference between Handicap Index and Course Handicap?
A Handicap Index is portable and describes your demonstrated ability. A Course Handicap converts it to the strokes you receive on one specific course and set of tees, using Course Handicap = Handicap Index x (Slope Rating / 113) + (Course Rating - par).
What does the number 113 mean in the handicap formula?
113 is the Slope Rating of a course of standard difficulty. Dividing by it scales your score to that neutral baseline, which is what makes a Handicap Index portable between courses of different difficulty.
Is this an official Handicap Index?
No. This calculator shows the arithmetic of the World Handicap System, but an official Handicap Index can only be issued by an authorized golf club or association. This tool also cannot apply the daily Playing Conditions Calculation, the exceptional score reduction, or the cap on upward movement, because those need your full scoring history.
What is a target score?
Add your Course Handicap to the par of the tees you are playing. That total is the score you shoot when you play exactly to your handicap - which typically happens in about 20-25% of rounds.
Find a course to play
Course Rating and Slope Rating are printed on the scorecard at the course. Browse the registry to find somewhere to put your handicap to work:
- Golf courses by state — all 50 ranked
- Public golf courses by state
- Nine-hole golf courses by state
- Public vs private golf courses in the US
"World Handicap System", "WHS", "Handicap Index", "Course Handicap" and "Score Differential" are trademarks of the United States Golf Association and R&A Rules Limited. This page is not affiliated with, endorsed by, or issued under the authority of either body.