Gold Melt Calculator estimates the intrinsic value of a gold item, using its weight, karat purity, and current spot price, along with an estimated dealer payout after margins.
Gold Melt Calculator: Estimate the Intrinsic Value of Scrap or Jewelry Gold
This Gold Melt Calculator converts a gold item’s gross weight, karat purity, and the current spot price into its intrinsic elemental value, then applies a dealer margin to estimate a cash payout. It is used by people evaluating jewelry, coins, or scrap gold for sale, or checking a dealer’s quoted offer against the underlying melt value.
Gold Melt Calculator Inputs: Weight, Karat, Spot Price, and Dealer Margin
Enter Gold Spot Price (per troy oz), Gold Weight with a unit (grams, troy oz, oz, dwt, grains, or kg), Karat Purity (1-24), and Dealer Margin (percent). The calculator outputs Total Melt Value, pure gold yield, an estimated dealer payout, and value density per gram, pennyweight, and troy ounce.
How the Gold Melt Calculator Computes Melt Value and Dealer Payout
Gold Weight is first standardized to grams using the exact troy-system conversion factors defined in NIST Handbook 44: 1 troy ounce equals 31.1034768 grams, 1 pennyweight equals 1.55517384 grams (1/20 troy oz), and 1 grain equals 0.06479891 grams (1/480 troy oz); the calculator’s ounce (avoirdupois) factor of 28.34952 grams is a close approximation of the exact 28.349523125-gram figure. Karat Purity is converted to a fineness ratio using the standard 24-karat scale used internationally in the gold trade, where 24 karat represents 100% pure gold:
$$\text{Purity} = \frac{\text{Karat}}{24}$$
Pure gold weight multiplies the standardized gross weight by that purity ratio, and Total Melt Value multiplies the pure gold weight (converted to troy ounces) by the entered Spot Price:
$$\text{Melt Value} = \left(\text{Gross Weight}_{g} \times \frac{\text{Karat}}{24} \div 31.1034768\right) \times \text{Spot Price}$$
Dealer Payout subtracts the entered Dealer Margin percentage from Melt Value. A common input mistake is entering a silver millesimal fineness figure, such as 925, into Karat Purity instead of the correct karat number for gold, which the field is not built to interpret.
Gold Weight must be greater than zero; Karat Purity must be greater than 0 and cannot exceed 24, since 24 karat is the maximum fineness on the karat scale; and Dealer Margin must fall between 0% and just under 100%, since a 100% margin would leave a payout of zero or less.
Gold Spot Price accepts zero, though a real market spot price of zero does not occur in practice. Alloy Value Density (value per gram, pennyweight, or troy ounce) divides Total Melt Value by the item’s gross, unrefined weight rather than its pure gold weight — a nuance worth noting, since it represents worth per gram of the item as weighed, not per gram of pure gold content, and the two figures diverge further as Karat Purity drops.
The melt value and payout figures are illustrative estimates based on the spot price and other figures entered — this is not an appraisal, a resale quote, or investment advice, and actual dealer offers can depend on assay costs, refining losses, and regional demand that this calculator does not model.
Visualizing How Dealer Margin Reduces Melt Value to a Payout
Gold Melt Calculator Questions: Karat, Units, and Edge Cases
How does karat purity affect the pure gold weight?
Karat divided by 24 gives the fineness ratio, since 24-karat is defined as 100% pure gold on the standard international karat scale used in the gold trade. An 18-karat item is 18 divided by 24, or 75% pure gold.
How does the calculator convert gold weight into a dollar melt value?
Weight is standardized to grams using NIST Handbook 44 conversion factors (1 troy oz = 31.1034768 g exactly), then Melt Value multiplies the pure gold content in troy ounces by the entered Spot Price per troy ounce.
Why is the value per gram different from the value per gram of pure gold?
Alloy Value Density divides Total Melt Value by the item’s gross, unrefined weight, not by its pure gold weight, so it represents worth per gram of the actual item as weighed, not per gram of pure gold content.
Why does the calculator reject a Dealer Margin of 100% or more?
Dealer Margin cannot reach or exceed 100%, since a 100% margin would mean a payout of zero or less, which is not a valid transaction outcome the calculator is built to represent.
What is the valid range for Karat Purity?
Karat Purity must be greater than 0 and cannot exceed 24, since 24-karat represents 100% pure gold — the maximum fineness on the karat scale — and there is no valid karat value above it.