How Are Golf Handicaps Calculated

Golf Score Differential Calculator

Calculate your official Score Differential for a single round based on World Handicap System (WHS) standards.

Total strokes after applying Net Double Bogey limits.

The difficulty for a scratch golfer (usually found on your scorecard).

A value between 55 and 155 (Average is 113).

Score Differential: 0.0

function calculateDifferential() { var score = parseFloat(document.getElementById('grossScore').value); var rating = parseFloat(document.getElementById('courseRating').value); var slope = parseFloat(document.getElementById('slopeRating').value); var resultDiv = document.getElementById('handicapResult'); var diffSpan = document.getElementById('differentialValue'); var textPara = document.getElementById('resultText'); if (isNaN(score) || isNaN(rating) || isNaN(slope) || slope <= 0) { alert("Please enter valid numbers for all fields. Slope must be greater than zero."); return; } // WHS Formula: (Adjusted Gross Score – Course Rating) x (113 / Slope Rating) var differential = ((score – rating) * 113) / slope; var roundedDiff = Math.round(differential * 10) / 10; diffSpan.innerHTML = roundedDiff.toFixed(1); var interpretation = ""; if (roundedDiff <= 0) { interpretation = "Excellent! This is a 'plus' handicap performance, better than a scratch golfer."; } else if (roundedDiff < 10) { interpretation = "Fantastic round! This identifies you as a single-digit handicap player."; } else if (roundedDiff < 20) { interpretation = "Solid performance. You are playing at a mid-handicap level."; } else { interpretation = "Great job finishing the round. Keep practicing to lower that differential!"; } textPara.innerHTML = interpretation + " Your Handicap Index is calculated by averaging your best 8 differentials out of your most recent 20 rounds."; resultDiv.style.display = 'block'; }

How Are Golf Handicaps Calculated?

Under the World Handicap System (WHS) introduced in 2020, golf handicaps are designed to be portable and fair across any course in the world. The calculation isn't just about your total strokes; it's a sophisticated math formula that accounts for the specific difficulty of the course and the tees you played.

The Score Differential Formula

Before you can find your Handicap Index, you must calculate a Score Differential for every round you play. This value represents the handicap level at which you played that specific day. The formula is:

Score Differential = (Adjusted Gross Score – Course Rating) x (113 / Slope Rating)

Key Terms Explained

• Adjusted Gross Score: This is your total score, but with a limit on how high you can score on any single hole. Under the WHS, the maximum hole score for handicap purposes is Net Double Bogey.
• Course Rating: This number (e.g., 72.4) tells you how many strokes a "scratch golfer" (0 handicap) should take to complete the course under normal conditions.
• Slope Rating: This measures the relative difficulty of a course for a "bogey golfer" compared to a scratch golfer. The average slope is 113. A higher slope (up to 155) means the course is significantly harder for non-experts.

From Differentials to a Handicap Index

Your official Handicap Index is not the average of all your scores. Instead, it is the average of your 8 best Score Differentials from your most recent 20 rounds. This system is designed to show your potential as a golfer rather than your average performance.

Example Calculation

Imagine you play a round and shoot an 88. The course has a Rating of 70.2 and a Slope of 130.

1. Subtract Rating from Score: 88 – 70.2 = 17.8
2. Divide 113 by Slope: 113 / 130 = 0.869
3. Multiply the results: 17.8 x 0.869 = 15.46

Your Score Differential for that day is 15.5. If this is one of your best 8 rounds, it will be used to calculate your index.

Why Use a Handicap?

The handicap system allows golfers of wildly different skill levels to compete fairly. A player with a 25 handicap can play a match against a 5 handicap, and by "getting strokes" on the hardest holes, both players have an equal chance of winning if they play well relative to their usual ability.