Golf Handicap Calculator
Find the handicap differential of a round.
Results update as you type.
How it works
Your golf handicap starts with a single round's handicap differential, and this golf handicap calculator computes that differential using the standard formula behind the world handicap system. Enter your adjusted gross score, the course rating, and the slope rating of the tees you played, and the tool returns the differential for that round. The differential is the building block of a handicap index. It expresses how well you scored relative to the difficulty of the specific course and tees, so a strong round on a brutal course can produce a lower differential than a mediocre round on an easy one. Your official handicap index is then derived from the average of your best recent differentials, which is why understanding a single round's differential helps you see how each score will influence your handicap. The calculation uses three inputs that together capture course difficulty. The course rating is the score a scratch golfer is expected to shoot, so subtracting it from your score shows how many strokes over that mark you were. The slope rating reflects how much harder the course plays for a bogey golfer than a scratch golfer, and dividing by it, then multiplying by the standard slope of 113, normalises your performance across courses of different difficulty. Golfers tracking their progress, estimating a new handicap, or comparing rounds played at different venues can use this calculator to turn any score into a comparable, meaningful number.
differential = (score − course rating) × 113 ÷ slope rating
A handicap differential measures how well you played one round relative to the difficulty of the course and set of tees. Subtracting the course rating from your adjusted score shows how many strokes above or below a scratch golfer's expected score you were. Multiplying by 113, the slope rating of a course of standard difficulty, and dividing by the actual slope rating scales that result so rounds played on easier and harder courses can be compared fairly on one standard.
Source:World Handicap System (handicap differential)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter adjusted gross score, course rating and slope rating.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Handicap differential updates instantly as you type — no button to press.
Frequently asked questions
What is a handicap differential?
A handicap differential is a number representing how well you played a single round relative to the difficulty of the course and tees. It is calculated from your adjusted score, the course rating, and the slope rating. Differentials from your recent rounds are averaged, using the best ones, to produce your handicap index. So each differential is a single-round measure that feeds into your overall handicap over time.
What is the difference between course rating and slope rating?
Course rating is the score a scratch, or zero-handicap, golfer is expected to shoot on the course, usually a number close to par, expressed to one decimal. Slope rating measures how much more difficult the course plays for a bogey golfer than for a scratch golfer, on a scale from 55 to 155, where 113 is standard difficulty. Together they let scores from different courses be compared fairly.
Why is the number 113 in the formula?
The value 113 is the slope rating of a course of standard, average difficulty. Dividing by the course's actual slope rating and multiplying by 113 rescales your differential to that standard baseline, so a round on a very hard course, which has a higher slope, is adjusted upward relative to one on an easier course. This normalisation is what makes differentials from different courses directly comparable.
What is an adjusted gross score?
Adjusted gross score is your total strokes with a maximum applied to any single hole under the net double bogey rule, which caps blow-up holes so one disastrous hole does not distort your handicap. For handicap purposes you use this adjusted figure rather than your raw total. Applying the cap keeps differentials representative of your typical ability rather than being skewed by an occasional very high hole score.
How many rounds do I need for an official handicap?
Under the world handicap system, a handicap index is calculated from the average of your best eight differentials out of your most recent twenty scores. You can obtain an initial index after posting as few as three eighteen-hole rounds, with adjustments applied while you have fewer scores. This calculator gives you a single round's differential, and collecting several lets you estimate where your index will settle.