18K Gold Calculator
Estimate 18K (750) gold value — the fine-jewelry standard for rings, chains, and luxury watches — in your currency and preferred weight unit.
Fineness
18K is 750 fine: exactly 75% pure gold, 25% alloy metals.
Common forms
European and designer fine jewelry, engagement rings, and gold watch cases.
Colors
Yellow, white, and rose 18K all contain identical gold — only the alloy metals differ.
How to calculate 18K gold value
Find the 750 or 18K hallmark — inside ring bands, on necklace clasps, or on watch case backs. Weigh the gold parts; for watches, only the case and bracelet count, not the movement or crystal. Select 18K purity so the calculator applies the 75% fine-gold ratio. Compare the melt value against offers, remembering designer pieces can be worth more than melt.
A worked 18K example
An 8 gram 18K ring at a $3,400 spot price: 8 ÷ 31.1035 = 0.2572 troy ounces, × 0.75 = 0.1929 ounces of fine gold, × $3,400 = about $656. If the ring carries a recognized brand name, check resale prices before selling it for melt — signed pieces from major houses often sell well above metal value.
White, yellow, and rose 18K are worth the same
An 18K white gold ring contains exactly as much gold as an 18K yellow gold ring of the same weight — 75%. White gold gets its color from palladium or nickel in the alloy plus rhodium plating; rose gold from extra copper. Buyers pay for the gold content, so color does not change melt value.
18K watches: what actually counts
A gold watch is quoted on the weight of its gold case, bezel, and bracelet only. The movement, dial, crystal, and steel parts are deducted. A typical 18K case contributes 30–60 grams; a full 18K bracelet can double that. For collectible brands, the watch is usually worth far more intact than melted.
What does the 750 stamp mean?
It marks 18K gold: 750 parts per thousand, or 75% pure gold. It is the most common fineness for European fine jewelry.
Is 18K white gold worth less than yellow?
No. Both are 75% gold by weight. The white color comes from alloy metals and rhodium plating, which have negligible scrap value either way.
Why is most luxury jewelry 18K instead of 24K?
18K keeps a rich gold color while being hard enough for stone settings and daily wear. It is the best balance of purity and durability for fine jewelry.