Handicap Calculator Golf

Golf Handicap Index Calculator (WHS)

Enter your Adjusted Gross Score, Course Rating, and Slope Rating for each of your recent rounds. The calculator will use the best differentials to determine your Handicap Index.

Round Scores:

Adjusted Gross Score Course Rating Slope Rating

Your Handicap Index will appear here.

function calculateHandicap() { var differentials = []; var numRounds = 10; // Number of input rows for (var i = 1; i 0) { // Handicap Differential = (Adjusted Gross Score – Course Rating) * 113 / Slope Rating var differential = (adjustedGrossScore – courseRating) * (113 / slopeRating); differentials.push(differential); } } var resultDiv = document.getElementById('handicapResult'); if (differentials.length < 3) { resultDiv.innerHTML = "Error: Please enter at least 3 valid rounds to calculate a Handicap Index."; resultDiv.style.backgroundColor = '#f8d7da'; resultDiv.style.borderColor = '#f5c6cb'; resultDiv.style.color = '#721c24'; return; } // Sort differentials in ascending order differentials.sort(function(a, b) { return a – b; }); var numDifferentialsToUse; if (differentials.length >= 20) { numDifferentialsToUse = 8; } else if (differentials.length >= 19) { numDifferentialsToUse = 8; } else if (differentials.length >= 17) { numDifferentialsToUse = 7; } else if (differentials.length >= 15) { numDifferentialsToUse = 6; } else if (differentials.length >= 12) { numDifferentialsToUse = 5; } else if (differentials.length >= 9) { numDifferentialsToUse = 4; } else if (differentials.length >= 7) { numDifferentialsToUse = 3; } else if (differentials.length >= 5) { numDifferentialsToUse = 1; // WHS uses 1 for 3-5 scores } else if (differentials.length >= 3) { numDifferentialsToUse = 1; // WHS uses 1 for 3-5 scores } else { // This case should be caught by the initial check, but as a fallback resultDiv.innerHTML = "Error: Not enough valid rounds to calculate a Handicap Index."; resultDiv.style.backgroundColor = '#f8d7da'; resultDiv.style.borderColor = '#f5c6cb'; resultDiv.style.color = '#721c24'; return; } // For 6 scores, WHS uses 2 best. For 7-8 scores, WHS uses 3 best. // Let's refine the logic for fewer than 8 scores based on WHS: if (differentials.length === 3 || differentials.length === 4 || differentials.length === 5) { numDifferentialsToUse = 1; } else if (differentials.length === 6) { numDifferentialsToUse = 2; } else if (differentials.length === 7 || differentials.length === 8) { numDifferentialsToUse = 3; } else if (differentials.length === 9 || differentials.length === 10 || differentials.length === 11) { numDifferentialsToUse = 4; } else if (differentials.length === 12 || differentials.length === 13 || differentials.length === 14) { numDifferentialsToUse = 5; } else if (differentials.length === 15 || differentials.length === 16) { numDifferentialsToUse = 6; } else if (differentials.length === 17 || differentials.length === 18) { numDifferentialsToUse = 7; } else if (differentials.length >= 19) { // For 19 or 20 scores numDifferentialsToUse = 8; } var sumOfBestDifferentials = 0; for (var j = 0; j < numDifferentialsToUse; j++) { sumOfBestDifferentials += differentials[j]; } var handicapIndex = sumOfBestDifferentials / numDifferentialsToUse; // Truncate to one decimal place (WHS standard) handicapIndex = Math.floor(handicapIndex * 10) / 10; resultDiv.innerHTML = "Your calculated Handicap Index is: " + handicapIndex.toFixed(1) + ""; resultDiv.style.backgroundColor = '#e9f7ef'; resultDiv.style.borderColor = '#d4edda'; resultDiv.style.color = '#155724'; }

Understanding the Golf Handicap Index

A golf handicap is a numerical measure of a golfer's ability, allowing players of different skill levels to compete fairly against each other. The lower the handicap, the better the golfer. Since 2020, the golf world largely operates under the World Handicap System (WHS), which aims to provide a consistent and equitable handicapping standard globally.

Key Terms in WHS:

• Adjusted Gross Score: This is your raw score for a round, adjusted for any maximum hole scores (e.g., Net Double Bogey under WHS). For this calculator, you should input your score after applying these adjustments.
• Course Rating: This is the USGA's evaluation of the playing difficulty of a course for a scratch golfer (a golfer with a handicap of zero). It's expressed in strokes to one decimal place (e.g., 72.5).
• Slope Rating: This is a measure of the relative difficulty of a course for a bogey golfer (a golfer with a handicap of approximately 20-24) compared to a scratch golfer. It ranges from 55 to 155, with 113 being the standard difficulty.
• Handicap Differential: This is the core calculation for each round played. It represents the difference between your adjusted gross score and the course rating, adjusted for the slope rating. The formula is:
  (Adjusted Gross Score - Course Rating) × 113 / Slope Rating
• Handicap Index: This is your overall measure of playing ability, calculated from the average of your best Handicap Differentials from your most recent 20 scores. It's expressed to one decimal place.
• Course Handicap: This is the number of strokes you receive for a specific course and set of tees. It's derived from your Handicap Index, the course's Slope Rating, Course Rating, and Par. This calculator focuses on the Handicap Index.

How the Handicap Index is Calculated (Simplified):

The World Handicap System calculates your Handicap Index based on the average of your 8 best Handicap Differentials from your most recent 20 scores. If you have fewer than 20 scores, the system uses a sliding scale:

• 3-5 Scores: Use the best 1 differential.
• 6 Scores: Use the best 2 differentials.
• 7-8 Scores: Use the best 3 differentials.
• 9-11 Scores: Use the best 4 differentials.
• 12-14 Scores: Use the best 5 differentials.
• 15-16 Scores: Use the best 6 differentials.
• 17-18 Scores: Use the best 7 differentials.
• 19-20 Scores: Use the best 8 differentials.

The average of these selected differentials is then truncated to one decimal place to become your Handicap Index.

How to Use This Calculator:

1. Gather Your Scores: Collect your Adjusted Gross Scores, Course Ratings, and Slope Ratings for your most recent rounds. You can typically find Course and Slope Ratings on the scorecard or the course's website.
2. Input Data: Enter the required information for each round into the respective fields. You can fill in as many rounds as you have, up to 10 in this calculator. For more rounds, you would typically use an official handicapping service.
3. Calculate: Click the "Calculate Handicap Index" button.
4. View Result: Your calculated Handicap Index will be displayed. This calculator applies the WHS rules for selecting the appropriate number of differentials based on the number of valid scores entered.

Example Calculation:

Let's say a golfer has the following 5 valid rounds:

Round	Adj. Gross Score	Course Rating	Slope Rating	Differential
1	85	72.5	130	(85 – 72.5) * 113 / 130 = 10.87
2	88	71.8	128	(88 – 71.8) * 113 / 128 = 14.30
3	82	70.1	125	(82 – 70.1) * 113 / 125 = 10.79
4	90	73.0	135	(90 – 73.0) * 113 / 135 = 14.22
5	86	72.0	129	(86 – 72.0) * 113 / 129 = 12.24

The differentials are: 10.87, 14.30, 10.79, 14.22, 12.24.

Sorted: 10.79, 10.87, 12.24, 14.22, 14.30.

For 5 scores, the WHS uses the best 1 differential.

Best differential: 10.79

Handicap Index = 10.79 (truncated to one decimal) = 10.7

This calculator provides a quick way to estimate your Handicap Index based on the WHS principles. For an official Handicap Index, you should register with your national golf association.