The calculation in full
- Weigh the item accurately in grams.
- Establish the standard — 375, 585, 750, 916 or 999 — from the hallmark.
- Multiply weight by fineness to get fine gold content in grams. A 12 g 750 ring holds 9 g of fine gold.
- Price that content against the gold market, which is quoted per troy ounce of 31.1035 grams.
- Assess anything that might make the item worth more than its metal: maker, stones, condition, collectability.
You can run steps one to three yourself with the gold purity conversion chart. Step four is where estimates and offers diverge, and it is explained in spot price versus what a gold buyer pays.
What people usually get wrong
- Weighing everything together. Mixed standards must be separated or the whole lot risks being treated as the lowest.
- Counting the stones. A stone's weight is not gold weight, and mounts are heavier than they look.
- Assuming a stamp is a hallmark. Plated items carry convincing-looking marks.
- Using kitchen scales. A 2 gram error on a 22ct bangle is a real amount of gold.
Where the market price comes from
Gold trades continuously worldwide and is quoted in US dollars per troy ounce, with a widely used London benchmark set by auction twice each business day. Sterling values also move with the pound to dollar exchange rate, so a UK seller is exposed to both. Gold Up does not publish a price on this site — the figure that matters is the one applying when your item is valued.
When an item is worth more than its gold
Signed pieces, period jewellery, good diamonds and collectable coins can exceed metal value. Anything unusual should be identified before it is treated as scrap.
No estimate is an offer. An offer can only follow weighing of the actual items.
