How to Calculate Gold Exchange Rate Per Gram

Calculating Gold Exchange Rate

Knowing how the gold exchange rate per gram is calculated gives you confidence when selling your gold. This guide walks you through how that value is calculated, and how to use our calculator to estimate your gold’s melt value using the current rate from our gold spot price page.

What Does Gold Exchange Rate Per Gram Mean?

The gold exchange rate per gram is simply the market value of one gram of pure gold. It’s based on the current global spot price, which reflects what gold trades for in U.S. dollars per troy ounce.

Since one troy ounce equals 31.1035 grams, you can find the price per gram using a simple conversion:

Spot price ÷ 31.1035 = gold price per gram

For example, if gold’s spot price is $2,350 per troy ounce, the rate per gram is roughly $75.55. That’s the base value before factoring in purity and weight.


How Gold Value Is Calculated

Every gold item’s value comes down to three things:
Weight – measured in grams
Purity – based on karats or fineness
Spot price – the current market rate

Gold purity is expressed in karats, with 24K being pure gold. You can convert karats to a decimal percentage using this formula:

Purity = Karat ÷ 24


Examples:
24k = 1.00 (100% pure)
18k = .75 (75% pure)
14k = .583 (58.3% pure)
Once you know purity, multiply it by the weight (in grams) and the current price per gram of pure gold.

The Formula for Calculating Gold Price Per Gram

Value = Weight (g) × Purity × Spot Price per Gram

Let’s use this example:
Weight: 20g
Purity: 14k
Spot Price $75.55 per gram

Value = 20 × 0.583 × 75.55 = $879.40

This number represents the melt value—what your gold is worth solely for its metal content, not for its design, brand, or gemstones.

Not all gold is pure or in perfect condition. If you’re selling scrap gold—like broken chains, single earrings, or damaged rings—the same formula still applies. The calculator helps estimate what you’d get based on gold content, even if the piece isn’t wearable.

However, remember that jewelers and refiners may deduct small percentages to cover refining costs. If you want an exact offer, bring your items to any Precious Metals Refinery location for a free in-person appraisal and instant offer.

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