18K Gold Calculator: What 18 Karat Gold Is Worth Today

What the 750 Stamp Actually Tells You

Flip over a Cartier bangle, a Rolex clasp, or a fine Italian chain and you'll usually find a tiny 750 — the millesimal fineness mark meaning 750 parts gold per thousand. That is exactly what 18 karat means: 18 of 24 parts gold, or 75% pure. The remaining 25% is an alloy mix — copper and silver for yellow gold, extra copper for rose, palladium or nickel for white — that gives the metal its working hardness and its color.

18K is the default karat of European and luxury jewelry for a reason. Much of Europe historically reserved the label of fine gold jewelry for 18K and up, and the big houses — Cartier, Van Cleef & Arpels, Bulgari — build almost everything in it. Rolex famously casts its own 18K alloys in-house. So when you're holding 18K, you're holding the karat of the high end, and that has consequences for value we'll get to below.

If the stamp says 750, 18K, or 18KT, the math on this page applies directly. If you're looking at a different number, our gold purity chart decodes every fineness mark in one table, and our guide to gold hallmarks covers the maker's marks, assay symbols, and plating codes crowding that tiny patch of metal.

The Per-Gram Math, With a Table You Can Sanity-Check

The formula never changes:

(spot price per troy ounce ÷ 31.103) × 0.75 × weight in grams = 18K melt value

Assume gold at $4,400 per troy ounce — inside the recent trading band of roughly $4,300–$4,500. Divide by 31.103 and pure gold runs $141.46 per gram. Multiply by 0.75 and 18K works out to $106.10 per gram. From there it's just weight:

Two traps hide in that table. First, buyers who quote in pennyweights aren't necessarily cheating you, but the smaller-sounding unit makes a low offer harder to spot at a glance. Second, the troy ounce is 31.103 grams — not the 28.35-gram ounce your kitchen scale thinks in. Confuse the two and you misprice your gold by almost 10% before negotiations even begin. The 18K gold calculator above pulls the live spot price and runs this exact math, so you never have to redo it when the market moves.

A Worked Example: One 15.2-Gram Rope Chain

Say you inherit an 18K rope chain stamped 750 that weighs 15.2 grams on a pocket scale. At our assumed $4,400/oz price:

15.2 g × $106.10 = $1,612.72 melt value

That's the ceiling — the value of the raw gold itself. Nobody pays 100% of melt, because every buyer needs margin to cover refining costs and profit. Using the payout ranges we see across the industry, the realistic offers on that one chain spread out like this: an online refiner paying 70–90% of melt would offer $1,129–$1,451; a local coin or bullion dealer at 65–85% lands between $1,048 and $1,371; a jewelry store's typical 50–75% means $806–$1,210; and a pawn shop's 40–60% drops the range to $645–$968.

Read that again: the gap between the best and worst realistic offer on a single chain is roughly $800. That spread is the entire argument for running your own numbers through a gold calculator before you walk into anyone's shop — and for collecting at least three quotes before you accept one. The seller who knows the chain melts at $1,612 negotiates from the ceiling down; the seller who doesn't negotiates from the first lowball up.

Before You Melt: The Designer Premium Problem

Here's where 18K differs from 14K and 10K scrap: a meaningful share of 18K pieces are worth more intact than melted. Because 18K is the house karat of the luxury brands, signed pieces — Cartier, Van Cleef & Arpels, Tiffany, Bulgari — routinely change hands on the secondhand market well above their melt value. A Cartier Love bracelet's raw gold might pencil out to a few thousand dollars; the bracelet itself, with its screws and its signature, typically sells for considerably more.

A refiner pays for the gold. A collector pays for the name, the design, and the gold. If your 18K piece carries a name, get the collector's number before you take the refiner's.

The same logic protects 18K Rolex and other Swiss watch bracelets (sell the watch whole — never scrap the band), antique pieces with maker's marks, and anything with documented provenance or its original box and papers. The checklist is short: look for a brand signature next to the 750 stamp, search recent sold listings for comparable pieces, and get an offer from a jewelry reseller or auction consigner before talking to any scrap buyer.

If the piece is generic — an unbranded chain, a single earring, a dated setting nobody wants — then melt value is the honest benchmark, and the calculator above is your negotiating floor.

18K or 14K: What You Trade Either Way

Per gram, 18K beats 14K by simple arithmetic: 75% purity against 58.33%. At our assumed $4,400/oz, that's $106.10 per gram versus $82.52 — about 29% more money for every gram of 18K you sell. (You can run the lower-karat numbers on our 14K gold calculator.)

As jewelry, though, the trade-off cuts the other way. The extra alloy in 14K makes it measurably harder and more scratch-resistant, which is why American engagement rings and daily-wear pieces lean 14K, while European and luxury jewelry lean 18K for the richer, warmer color and the prestige of the higher karat. Neither is better in the abstract; they're tuned for different jobs — one for durability, one for color and cachet.

For a seller, the practical takeaway is sorting. Never let a buyer weigh mixed karats together: a parcel of 18K weighed and priced as 14K silently donates that 29% premium to the buyer, and it happens more often through sloppiness than malice. Sort by stamp, weigh each karat separately, and price each pile on its own purity. At the far end of the scale, 10K gold is worth barely more than half of 18K per gram, which makes mixed-lot pricing an even more expensive mistake.

What Buyers Will Actually Put on the Table

18K is desirable scrap. Its high purity means a refiner recovers more gold per ounce processed, so clean 18K parcels often land near the top of each buyer type's payout range — but only if you make buyers compete. The hierarchy is consistent: online refiners pay roughly 70–90% of melt, local coin and bullion dealers 65–85%, jewelry stores 50–75%, pawn shops 40–60%, and the mail-in operations that advertise on daytime TV as little as 20–50%.

A few field-tested rules. Weigh your gold yourself before any appointment, so you can't be quietly short-weighed. Ask every buyer for their price per gram of 18K — not a lump sum — so quotes are directly comparable. Get offers in writing where possible. And treat anyone who won't explain their price formula as a no. The FTC's guidance on selling gold jewelry is worth five minutes before you ship anything to a mail-in buyer; it covers the appraisal and reimbursement practices reputable operations follow.

One last 18K-specific warning: because the karat commands real money, it attracts counterfeits — gold-plated pieces wearing fake 750 stamps turn up constantly. If a deal involves any doubt, a $25 acid testing kit or a jeweler's electronic tester settles the question before money moves.

Frequently Asked Questions