function calculateGoldRate() {
var basePrice = parseFloat(document.getElementById('basePrice24k').value);
var unitDivisor = parseFloat(document.getElementById('priceUnit').value);
var carat = parseFloat(document.getElementById('targetCarat').value);
var weight = parseFloat(document.getElementById('jewelryWeight').value);
// Validation
if (isNaN(basePrice) || basePrice <= 0) {
alert("Please enter a valid current market price for 24K gold.");
return;
}
if (isNaN(weight) || weight <= 0) {
weight = 1; // Default to 1 if empty or invalid
}
// Logic:
// 1. Calculate Price Per Gram of 24K
var pricePerGram24k = basePrice / unitDivisor;
// 2. Calculate Purity Factor (Carat / 24)
var purityFactor = carat / 24;
// 3. Calculate Price Per Gram of Target Carat
var pricePerGramTarget = pricePerGram24k * purityFactor;
// 4. Calculate Total Value
var totalValue = pricePerGramTarget * weight;
// 5. Calculate Percentage
var percentage = (purityFactor * 100).toFixed(2);
// Formatting currency (generic, no specific symbol enforced to keep it international)
function formatMoney(num) {
return num.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
// Display Results
document.getElementById('resPurity').innerHTML = carat + " Karat";
document.getElementById('resPercentage').innerHTML = percentage + "%";
document.getElementById('resCaratLabel').innerHTML = carat + "K";
document.getElementById('resRatePerGram').innerHTML = formatMoney(pricePerGramTarget);
document.getElementById('resWeightLabel').innerHTML = weight;
document.getElementById('resTotalValue').innerHTML = formatMoney(totalValue);
document.getElementById('resultBox').style.display = "block";
}
How to Calculate Gold Rate Per Carat
Understanding how gold prices are calculated based on karat purity is essential for anyone buying jewelry, investing in bullion, or trading in precious metals. The market price is almost always quoted for 24K (pure gold), but most jewelry is made from 22K, 18K, or 14K gold. This guide and calculator will help you determine the exact value of gold based on its specific purity level.
Understanding Gold Purity (Karats)
Gold purity is measured in "Karats" (K), with 24 Karat being the standard for pure gold. However, pure gold is too soft for durable jewelry, so it is often mixed with other metals like copper, silver, or zinc to create alloys.
24K Gold: 99.9% Pure. Used for coins and bars.
22K Gold: 91.67% Pure. The standard for high-quality jewelry (especially in Asia and the Middle East).
18K Gold: 75.0% Pure. Common in diamond jewelry and watches.
14K Gold: 58.3% Pure. Popular in the US for everyday wear.
The Formula to Calculate Gold Rate
To calculate the rate of gold for any specific carat, you must first know the current market price of 24K gold per unit (gram, ounce, etc.). The logic follows a simple ratio calculation.
Formula:
Rate of X Karat = (Current Price of 24K Gold / 24) × X
Step-by-Step Calculation Example
Let's say the current market price for 10 grams of 24K gold is 60,000. You want to find the price of 1 gram of 22K gold.
Find 24K price per gram: 60,000 / 10 = 6,000 per gram.
Determine the purity factor: For 22K, the purity is 22/24.
So, the intrinsic gold value of 1 gram of 22K gold is 5,500.
Purity Conversion Table
Use this table to quickly understand the gold content percentage for different karat levels.
Karats (K)
Purity (Parts per 24)
Gold Percentage (%)
Common Usage
24K
24/24
99.9%
Bullion, Coins
22K
22/24
91.7%
Jewelry
21K
21/24
87.5%
Middle Eastern Jewelry
18K
18/24
75.0%
Diamond Settings, Watches
14K
14/24
58.3%
Durable Jewelry (US Standard)
9K
9/24
37.5%
Affordable Jewelry
Additional Costs: Making Charges and Wastage
While the calculator above determines the raw value of the gold based on purity, the final retail price of jewelry includes additional costs:
Making Charges: The labor cost involved in designing and manufacturing the jewelry. This can range from 3% to 25% depending on the intricacy of the design.
Wastage (VA): In some markets, jewelers charge for gold "wasted" during the manufacturing process (cutting, soldering, melting).
Taxes: GST, VAT, or sales tax applicable in your region.
To calculate the final price of a jewelry piece: (Gold Rate per Gram × Weight) + Making Charges + Taxes.
Why Does Gold Rate Fluctuate?
Gold rates change daily based on international market trends. Key factors include:
Supply and Demand: High demand during wedding seasons or festivals drives prices up.
Currency Fluctuations: Since gold is traded internationally in USD, the strength of your local currency against the dollar affects local rates.
Central Bank Reserves: Buying and selling by central banks influences global prices.
Inflation: Gold is often seen as a hedge against inflation, so prices may rise when inflation is high.