The Gold Melt Value Calculator helps you estimate the intrinsic worth of gold based on its weight, purity, and the current market price of pure gold. This is particularly useful for individuals looking to sell scrap gold, old jewelry, or any other gold items. The value is determined by the amount of pure gold content within the item, often referred to as its "melt value."
How it Works: The Math Behind the Value
Calculating the melt value involves a few key steps:
Determining Pure Gold Content: Gold jewelry and other items are rarely made of 100% pure gold (24 Karat). Instead, they are alloyed with other metals (like copper, silver, or nickel) to increase durability and reduce cost. The Karat system measures the purity of gold:
24K: 99.9% pure gold (considered pure)
22K: 91.7% pure gold
18K: 75.0% pure gold
14K: 58.3% pure gold
10K: 41.7% pure gold
To find the actual weight of pure gold in your item, you multiply the total weight of the item by its purity percentage.
Applying the Spot Price: The "spot price" is the current market price for one troy ounce or gram of pure gold. This price fluctuates daily based on global market conditions.
Calculating the Melt Value: The final melt value is calculated by multiplying the weight of pure gold (determined in step 1) by the current spot price of gold per gram.
The Formula
The calculation performed by this calculator can be represented by the following formula:
Melt Value = (Weight of Gold in grams * Purity Percentage) * Spot Price per Gram
Where:
Weight of Gold in grams: The total weight of the gold item in grams.
Purity Percentage: The proportion of pure gold in the item, derived from its Karat rating (e.g., 14K = 0.583, 18K = 0.750, 24K = 0.999).
Spot Price per Gram: The current market price for one gram of pure gold.
Example Calculation
Let's say you have:
Weight of Gold: 50 grams
Purity: 18K (which is 75.0% pure gold)
Spot Price: $65.50 per gram
Here's how the calculation would proceed:
Pure Gold Content: 50 grams * 0.750 = 37.5 grams of pure gold
Melt Value: 37.5 grams * $65.50/gram = $2456.25
So, the estimated melt value of this gold item would be $2456.25.
When to Use This Calculator
Selling Scrap Gold: To get a fair estimate before selling broken jewelry, dental gold, or other gold scraps.
Evaluating Inherited Items: To understand the potential value of gold pieces passed down through generations.
Investment Decisions: To gauge the underlying value of gold-based investments.
Remember that this calculator provides an estimated melt value. Actual selling prices may vary based on the buyer, refining costs, and market conditions at the time of sale.
function getPurityPercentage(karat) {
karat = String(karat).toLowerCase().replace('k', ").trim();
var purityMap = {
"24": 0.999,
"22": 0.917,
"18": 0.750,
"14": 0.583,
"10": 0.417
};
return purityMap[karat] || 0;
}
function calculateMeltValue() {
var weightInput = document.getElementById("goldWeight");
var purityInput = document.getElementById("goldPurity");
var spotPriceInput = document.getElementById("spotPrice");
var resultDiv = document.getElementById("result");
var weight = parseFloat(weightInput.value);
var purityStr = purityInput.value;
var spotPrice = parseFloat(spotPriceInput.value);
if (isNaN(weight) || isNaN(spotPrice) || weight <= 0 || spotPrice <= 0) {
resultDiv.innerText = "Please enter valid positive numbers for weight and spot price.";
resultDiv.style.color = "red";
return;
}
var purityPercentage = getPurityPercentage(purityStr);
if (purityPercentage === 0) {
resultDiv.innerText = "Please enter a valid Karat value (e.g., 14K, 18K, 24K).";
resultDiv.style.color = "red";
return;
}
var pureGoldWeight = weight * purityPercentage;
var meltValue = pureGoldWeight * spotPrice;
// Format the result to two decimal places for currency
var formattedMeltValue = meltValue.toFixed(2);
resultDiv.innerText = "Estimated Melt Value: $" + formattedMeltValue;
resultDiv.style.color = "#004a99"; // Professional blue for success
}