.ghin-handicap-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 10px;
background-color: #f9f9f9;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.ghin-handicap-calculator-container h2 {
color: #2c3e50;
text-align: center;
margin-bottom: 25px;
font-size: 1.8em;
}
.ghin-handicap-calculator-container .input-group {
display: flex;
flex-wrap: wrap;
gap: 15px;
margin-bottom: 15px;
align-items: center;
border: 1px solid #dcdcdc;
padding: 10px;
border-radius: 8px;
background-color: #ffffff;
}
.ghin-handicap-calculator-container .input-group label {
flex: 1 1 100%;
font-weight: bold;
color: #34495e;
margin-bottom: 5px;
font-size: 0.95em;
}
.ghin-handicap-calculator-container .input-group input[type="number"] {
flex: 1 1 calc(33% – 10px); /* Three inputs per row */
padding: 10px 12px;
border: 1px solid #ccc;
border-radius: 5px;
font-size: 1em;
box-sizing: border-box;
transition: border-color 0.3s ease;
}
.ghin-handicap-calculator-container .input-group input[type="number"]:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 5px rgba(0, 123, 255, 0.2);
}
.ghin-handicap-calculator-container .round-header {
flex: 1 1 100%;
font-weight: bold;
color: #2980b9;
margin-bottom: 10px;
font-size: 1.1em;
border-bottom: 1px dashed #a0a0a0;
padding-bottom: 5px;
}
.ghin-handicap-calculator-container button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #28a745;
color: white;
border: none;
border-radius: 5px;
font-size: 1.1em;
cursor: pointer;
transition: background-color 0.3s ease, transform 0.2s ease;
margin-top: 20px;
}
.ghin-handicap-calculator-container button:hover {
background-color: #218838;
transform: translateY(-2px);
}
.ghin-handicap-calculator-container #result {
margin-top: 25px;
padding: 15px;
border: 1px solid #d4edda;
background-color: #e9f7ef;
border-radius: 8px;
font-size: 1.2em;
color: #155724;
text-align: center;
font-weight: bold;
min-height: 50px;
display: flex;
align-items: center;
justify-content: center;
}
.ghin-handicap-calculator-container #result.error {
border-color: #f5c6cb;
background-color: #f8d7da;
color: #721c24;
}
.ghin-handicap-calculator-container .calculator-info {
margin-top: 30px;
padding-top: 20px;
border-top: 1px solid #e0e0e0;
color: #555;
line-height: 1.6;
}
.ghin-handicap-calculator-container .calculator-info h3 {
color: #2c3e50;
margin-bottom: 15px;
font-size: 1.5em;
}
.ghin-handicap-calculator-container .calculator-info p {
margin-bottom: 10px;
}
.ghin-handicap-calculator-container .calculator-info ul {
list-style-type: disc;
margin-left: 20px;
margin-bottom: 10px;
}
.ghin-handicap-calculator-container .calculator-info li {
margin-bottom: 5px;
}
@media (max-width: 600px) {
.ghin-handicap-calculator-container .input-group input[type="number"] {
flex: 1 1 calc(50% – 10px); /* Two inputs per row on smaller screens */
}
}
@media (max-width: 400px) {
.ghin-handicap-calculator-container .input-group input[type="number"] {
flex: 1 1 100%; /* One input per row on very small screens */
}
}
GHIN Golf Handicap Calculator
Understanding Your GHIN Golf Handicap
A GHIN (Golf Handicap Information Network) Handicap Index is a numerical measure of a golfer's potential ability, used to allow players of different skill levels to compete fairly. It's calculated using the World Handicap System (WHS), which aims to make handicapping consistent globally.
Key Components of Handicap Calculation:
- Adjusted Gross Score (AGS): This is your raw score for a round, adjusted for any maximum hole scores (e.g., Net Double Bogey) to account for unusually high scores on individual holes.
- Course Rating: This represents the playing difficulty of a course for a scratch golfer (a golfer with a Handicap Index of 0.0). It's expressed in strokes to one decimal place (e.g., 72.1).
- Slope Rating: This indicates the relative difficulty of a course for a "bogey golfer" (a golfer with a Handicap Index of approximately 20-24) compared to a scratch golfer. It ranges from 55 to 155, with 113 being the standard. The higher the Slope Rating, the more difficult the course is for a bogey golfer.
- Handicap Differential: This is the core calculation for each round. It converts your score on a specific course into a value that can be compared across different courses. The formula is:
(Adjusted Gross Score - Course Rating) × 113 / Slope Rating
How the Handicap Index is Calculated (WHS):
The World Handicap System calculates your Handicap Index based on the average of your best Handicap Differentials from your most recent 20 scores. If you have fewer than 20 scores, a sliding scale is used:
- 3-5 Scores: The lowest 1 differential.
- 6 Scores: The lowest 2 differentials.
- 7-8 Scores: The lowest 3 differentials.
- 9-10 Scores: The lowest 4 differentials.
- …and so on, up to 8 differentials for 17-20 scores.
The average of these selected differentials is then truncated to one decimal place to become your Handicap Index. This calculator uses up to 10 rounds to provide an estimate based on this WHS methodology.
Using This Calculator:
Input your Adjusted Gross Score, the Course Rating, and the Slope Rating for each of your recent rounds. You can leave fields blank if you have fewer than 10 rounds. The calculator will identify valid entries and apply the WHS rules to estimate your Handicap Index.
Note: This calculator provides an estimate based on the core WHS formula. Official GHIN Handicap Indexes may include additional adjustments like Playing Conditions Calculation (PCC), exceptional score reductions, and soft/hard caps, which are not factored into this simplified tool.
function calculateHandicap() {
var differentials = [];
var resultDiv = document.getElementById("result");
resultDiv.className = ""; // Clear any previous error classes
for (var i = 1; i = 0 && cr >= 0 && sr > 0) {
var differential = (ags – cr) * 113 / sr;
differentials.push(differential);
}
}
if (differentials.length = 3 && numScores = 7 && numScores = 9 && numScores <= 10) { // For 9 or 10 scores, use the best 4
numToUse = 4;
} else {
// This case should ideally not be hit if input is capped at 10, but good for robustness
resultDiv.innerHTML = "An unexpected number of scores was processed. Please check inputs.";
resultDiv.className = "error";
return;
}
var sumOfBestDifferentials = 0;
for (var j = 0; j < numToUse; j++) {
sumOfBestDifferentials += differentials[j];
}
var handicapIndex = sumOfBestDifferentials / numToUse;
// Truncate to one decimal place
handicapIndex = Math.floor(handicapIndex * 10) / 10;
resultDiv.innerHTML = "Your Estimated Handicap Index:
" + handicapIndex.toFixed(1) + "";
}