How is Handicap Calculated in Golf

Golf Score Differential Calculator

Total strokes after applying Net Double Bogey limit.

Usually found on the scorecard (e.g., 72.4).

Relative difficulty for bogey golfers (55 to 155).

Your Score Differential: 0.0

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How is a Golf Handicap Calculated?

Calculating a golf handicap might seem like complex trigonometry, but under the World Handicap System (WHS) introduced in 2020, the process is streamlined to ensure golfers of different abilities can compete fairly. A handicap doesn't represent your average score; it represents your potential score.

1. The Score Differential Formula

Before you get a Handicap Index, every round you play is converted into a "Score Differential." This number normalizes your score based on the difficulty of the course you played. The formula is:

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

• Adjusted Gross Score: Your total strokes, but limited by "Net Double Bogey" (the maximum score you can take on any hole for handicap purposes).
• Course Rating: A number (usually between 67 and 77) representing the expected score for a "scratch" golfer.
• Slope Rating: A number representing the relative difficulty of a course for a "bogey" golfer compared to a scratch golfer. 113 is the standard neutral slope.

2. Determining the Handicap Index

Your actual Handicap Index is the average of your 8 best Score Differentials from your most recent 20 rounds. If you have fewer than 20 rounds recorded, a sliding scale is used (e.g., if you have only 5 rounds, only the lowest 1 is used).

Practical Example

Imagine you shot an 85 on a course with a 71.2 Course Rating and a 125 Slope Rating:

1. Subtract Rating from Score: 85 – 71.2 = 13.8
2. Divide 113 by Slope: 113 / 125 = 0.904
3. Multiply: 13.8 x 0.904 = 12.47

Your Score Differential for that round is 12.5. If this is one of your best 8 rounds out of your last 20, it will be averaged to create your Handicap Index.

What is a Course Handicap?

Once you have a Handicap Index (e.g., 10.4), you use it to find your Course Handicap for the specific tees you are playing today. This tells you exactly how many strokes you get on that specific course:

Course Handicap = Index x (Slope / 113) + (Course Rating – Par)

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 diffVal = document.getElementById('diffVal'); var diffDesc = document.getElementById('diffDesc'); if (isNaN(score) || isNaN(rating) || isNaN(slope)) { alert("Please enter valid numbers for all fields."); return; } if (slope 155) { alert("Slope rating usually falls between 55 and 155."); } // Calculation: (Score – Rating) * (113 / Slope) var differential = (score – rating) * (113 / slope); var roundedDiff = differential.toFixed(1); diffVal.innerHTML = roundedDiff; var interpretation = ""; if (roundedDiff <= 0) { interpretation = "That is a scratch or better-than-scratch performance!"; } else if (roundedDiff < 10) { interpretation = "This reflects a low-handicap performance."; } else if (roundedDiff < 20) { interpretation = "This is a solid mid-handicap round."; } else { interpretation = "This score differential will be averaged with your other best rounds to find your index."; } diffDesc.innerHTML = "Based on a score of " + score + " on a course with a " + rating + " rating and " + slope + " slope, your differential is " + roundedDiff + ". " + interpretation; resultDiv.style.display = "block"; resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }