How to calculate the gold price per gram
Why a troy ounce is not simply 30 grams, how fineness changes the metal value and why a dealer price rarely equals the spot reference.
The common basis: the troy ounce
International gold is commonly quoted in US dollars per troy ounce. One troy ounce equals exactly 31.1034768 grams, so the fine-gold price per gram is the ounce price divided by 31.1034768. A conversion into another currency also requires the corresponding exchange rate at a defined time.
Fineness changes the metal value
Investment gold marked 999.9 is almost pure gold. An item marked 750 contains 75 per cent gold, so 20 grams contain a theoretical 15 grams of fine gold. Only that content is multiplied by the spot reference; craftsmanship and collector value follow different rules.
Why dealer prices differ
Spot is a wholesale reference for standardised gold. A dealer also covers sourcing, testing, financing, insurance, staffing and margin. Retail sales are therefore usually above material value and repurchase prices below it; the distance becomes visible as a spread.
Formula: weight in grams × fineness ÷ 1,000 × spot price per gram. The result is an indicative material value, not a binding offer.