18ct gold price per gram
18ct gold is three quarters pure gold, whatever its colour, and the number stamped on it is 750. Type the weight of your piece below to see what the gold in it is worth today. Yellow, white and rose 18ct differ only in what makes up the other quarter. UK hallmarking law fixes 18ct at exactly 750 thousandths, so the calculator multiplies your weight by 0.75 and by the spot price of a gram of gold, which it works out from the price of a troy ounce in pounds read from gold-api.com, with the time of that price shown. Engagement rings, wedding bands and good watches are often 18ct, and many are set with stones, so the gold weighs less than the piece. The result is the metal value, the most a refiner’s customer can pay before its costs. Gold by Carat is an independent site, not a gold buyer or a dealer, and it prints no buyer’s prices.
Example: 10 g of 18ct (750 parts gold in 1,000)
£747.17
This is the value of the gold itself, at today’s price for pure gold. A buyer pays less.
| Pure gold inside | 7.500 g |
| Value of 1 g of 18ct | £74.72 |
Figures and rules checked by the site’s publisher, Radif Partners · How the values are worked out · Editorial policy
18ct gold price by weight
| Weight of 18ct | Pure gold inside | Metal value |
|---|---|---|
| 1 g | 0.75 g | £74.72 |
| 2 g | 1.50 g | £149.43 |
| 3 g | 2.25 g | £224.15 |
| 5 g | 3.75 g | £373.58 |
| 10 g | 7.50 g | £747.17 |
| 20 g | 15.00 g | £1,494 |
A plain 18ct wedding band of 4 or 5 g, a common weight, sits in the middle of that table. A man’s signet ring may weigh twice as much; a fine chain much less.
More detail below: tap a heading to open it.
Why 18ct is exactly 750
Eighteen twenty-fourths is three quarters, 750 thousandths, so here the law and the arithmetic match. UK hallmarking law lists 750 as one of the six standards for gold, and every item hallmarked 750 has been tested by an assay office and found to contain at least that much.
Colour, plating and stones
Colour comes from the quarter that is not gold. Yellow 18ct usually balances silver and copper; rose 18ct has more copper; white 18ct uses palladium or silver and is often plated with rhodium to brighten it. None of this changes the gold content, which is why a refiner pays the same per gram of 18ct whatever its colour. Plating is so thin it does not show on kitchen scales.
Stones do. A diamond, sapphire or cluster adds weight that is not gold, and some settings are hollow at the back. When a buyer removes the stones before weighing, its figure for the gold will be lower than the ring’s total weight. Ask for the stones back; they are yours and the scrap price does not pay for them.
Check an offer for this gold
Example: this offer pays
70.3%
of the £747.17 the gold is worth in this example of 10 g of 18ct
Is it a good offer? No law or official body publishes what buyers pay, so nobody can tell you a normal percentage. Your yardstick is other quotes: ask one or two other buyers about the same gold today, and if one pays clearly less than the others, walk away. 100% would be all the gold is worth. Every 10 percentage points on this gold is £74.72.
Got two or three quotes? Compare them side by side →
| Value of the gold | £747.17 |
| Offer | £525.00 |
| Difference kept by the buyer | £222.17 |
| Offer per gram | £52.50 |
What the buyer keeps pays for melting and refining, staff and the risk that the price falls: it is not all profit.
Before you say yes
- Ask for the weight and the carat the buyer wrote down, and compare them with yours.
- Get one or two more quotes for the same gold today: the highest share is the best offer.
- A signed, antique or stone-set piece may be worth more to a second-hand jeweller than its gold.
Selling an 18ct piece
Because 18ct is three times as rich as 9ct by weight, every percentage point on the offer is worth more. A 10 percentage point gap on 10 g of 18ct is £74.72 at our recorded price, compared with £37.36 on 10 g of 9ct. That makes it more worthwhile to get two or three quotes for 18ct. If the piece was inherited, the page on selling inherited gold covers probate value and tax.