Golf Handicap Calculator
Estimate a handicap index from your recent scores using the World Handicap System method.
Results update as you type.
About this calculator
A golf handicap calculator estimates your Handicap Index from a list of recent adjusted gross scores. For each round it computes a Score Differential = (score − course rating) × 113 ÷ slope rating, which puts every course on the same scale regardless of difficulty. Under the World Handicap System the index is the average of your best differentials — the best 8 of your last 20 rounds once you have that many — with a reduced count and a small adjustment when you have fewer scores.
Worked example: on a course rated 72.0 with a slope of 113, a round of 85 gives a differential of (85 − 72) × 113 ÷ 113 = 13.0. Enter eight rounds and the tool averages your best differentials (using the WHS count for eight scores) to produce the index; a set of low-80s and high-80s rounds typically yields a mid-teens handicap.
Enter at least three rounds; the more you add, up to 20, the more representative the result. A differentials table shows which rounds were counted. This is a simplified single-course estimate, not an official USGA/R&A index.
Frequently asked questions
How is a golf handicap calculated?
Each round becomes a Score Differential of (score − course rating) × 113 ÷ slope. The World Handicap System then averages your lowest differentials — the best 8 of your last 20 rounds once you have 20, or a smaller set with a minor adjustment when you have fewer.
How many scores do I need for a handicap?
You can establish an index with as few as three 18-hole scores, though it uses only your single best differential then. Accuracy improves quickly as you approach 20 rounds, when the best 8 are averaged.
Is this an official handicap?
No. It is a simplified estimate assuming one course rating and slope for all rounds. An official Handicap Index also applies course-specific ratings, playing conditions and caps that this quick calculator does not.
What is a good golf handicap?
The average male handicap is around 14–16 and the average female around 27–28. Breaking into single digits (under 10) is considered a strong amateur; a scratch golfer has a handicap of 0, meaning they play to the course rating.
What are course rating and slope?
Course rating is the score a scratch golfer is expected to shoot on the course (near par, e.g. 72.0). Slope rates the difficulty for a bogey golfer relative to a scratch golfer, from 55 to 155 with 113 as the average. Both appear on the scorecard and normalise your differentials across courses.
What is a score differential?
It is a single round’s performance adjusted for course difficulty: (adjusted gross score − course rating) × 113 ÷ slope. It answers “how well did I play relative to this course” so rounds on hard and easy courses can be compared and averaged fairly.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/golf-handicap/curl
curl "https://calculator.free/api/v1/golf-handicap/?scores=85, 90, 88, 92, 87, 91, 84, 89"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/golf-handicap/?" + new URLSearchParams({
"scores": "85, 90, 88, 92, 87, 91, 84, 89"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.