18K Gold Calculator
See what 18K gold is worth from its weight. Three quarters of the metal is gold, and the stamp 750 matches that figure exactly.
18K gold value
1 troy oz = 31.1 g · 1 oz = 28.35 g · 1 dwt = 1.555 g
18K · 75.0%
Priced as 18 ÷ 24. The usual stamp is 750.
Common 18K weights
| Weight | Pure gold | Melt value |
|---|---|---|
| 1 g | 0.750 g | — |
| 5 g | 3.750 g | — |
| 10 g | 7.500 g | — |
| 20 g | 15.000 g | — |
| 50 g | 37.500 g | — |
| 1 oz | 21.262 g | — |
One piece at 18K, using the price above. 1 oz is the regular ounce (28.35 g), not a troy ounce (31.103 g).
Selling? See what buyers may pay for scrap gold.
Related karats
On this page
18K gold is 18 ÷ 24, which is exactly 75% gold. The fineness stamp is 750, and 750 parts per thousand is the same 75%. This page prices that purity.
18K is the usual karat of fine jewelry
Where American everyday jewelry settles on 14K, a lot of European fine jewelry and a lot of “better” US pieces settle on 18K. The gold fraction is high enough that the color reads as gold even in a small earring, and the alloy is still strong enough for a well-made ring. Italy, France and much of the European trade treat 750 as the ordinary solid-gold mark. You will see it on chains sold by weight, on engagement rings, and on watch cases that are actually gold rather than gold-capped.
The match between the name and the stamp is cleaner here than it is for 14K. Eighteen divided by 24 is exactly three quarters. Seven hundred and fifty parts per thousand is the same three quarters. There is no 0.2 point gap to explain, the way there is between 14K and the 585 stamp. If a piece says 18K or 750, this is the page. If it says 750 and someone has described it as “about 18K, maybe 14”, the stamp has already answered the question.
Watch cases deserve their own warning. A solid 18K case is worth pricing. The whole watch is not. Movements are steel, brass and jewels. Straps are leather or steel. A gold bezel on a steel watch is only the bezel. Weigh the gold part, or accept that a buyer who melts the case will not pay 18K on the weight of the movement you left attached. The calculator will happily price whatever grams you type, so the grams have to be the gold.
Richer color, and a softer metal
At 75% gold, less of the color is being diluted. Yellow 18K is warmer than yellow 14K made with a similar copper and silver mix. Rose 18K is a pink that still looks expensive rather than copper-bright, because the gold is the majority. White 18K is the alloy people argue about: nickel makes a hard white metal and bothers some wearers, palladium makes a softer white metal and costs more, and rhodium plating makes either of them look like white metal until the plate thins. Under the plate, it is still 75% gold if the stamp says so.
Softness is the price of that color. An 18K shank picks up fine scratches faster than a 14K shank. A thin 18K band can oval over years of wear. Prongs need to be thick enough, which is why a careful setter uses more metal on an 18K head than on a 14K head for the same stone. None of this changes melt. A scratched 18K ring has the same gold as the day it was polished, minus whatever tiny amount of metal the polish actually removed. Polishing a ring for years does remove a little gold. It does not remove the 25% that was never gold.
Hollow 18K rope chains are common in the weight-conscious part of the trade. They look like a 30 gram chain and weigh 8. The stamp can be honest and the visual can still mislead. Put the chain on a scale before you fall in love with the thickness. Eight grams of 18K is a real piece of gold. It is not thirty.
Reading an 18K mark, including on a watch
Inside the band, “18K”, “18kt” or “750”. On a watch, the mark is often between the lugs, on the case back, or both. “750” on the case back of a two-tone watch may refer only to the gold parts. Read the small words around it. “18K bezel” means the bezel, not the case. “Gold capped”, “gold filled” and “plaque or” are not solid 18K, whatever the yellow panels look like.
Some European pieces use a hallmark punch from an assay office next to the 750. The office mark tells you where it was tested. The 750 tells you the fineness. You do not add them together and you do not need the office in order to price the metal. You do need to be sure the 750 is on the part you are selling. A gold clasp on a plated chain is a clasp.
If the number is 740 or some other near miss, do not round it to 18K on this page. The karat here is locked. Type the odd fineness into the gold karat calculator, see the percent, and price that percent as Custom purity on the gold calculator. Rounding 740 up to 750 is how a quote gets optimistic.
An 8 gram 18K chain at the live price
Eight grams is a believable weight for a light 18K wheat chain or a finer curb, the sort of chain bought as jewelry rather than as a bullion-like necklace. A heavy 18K Cuban will be several times that. Start with 8 grams, then replace the number with yours. The example uses the price sitting in the calculator, so a Custom price and a live price do not get mixed.
The worked example uses 8 gram 18K chain and fills in from the price in the calculator.
Selling the chain is a second step. Melt is the ceiling for scrap, not the check a refiner writes. The scrap gold calculator applies typical payout ranges to a melt value. An 18K piece does not get a special payout percentage on that page. It gets a higher melt, because more of each gram is gold, and then the same kind of discount a buyer takes on any karat.
Units matter more on fine chain because the weight is small and a unit mistake is a large share of it. One pennyweight is 1.55517384 g. One troy ounce is 31.1034768 g. One regular ounce is 28.349523125 g. Eight grams is a little over five pennyweight. If a jeweler’s scale says 5 dwt and you type 5 into a gram field, you have understated the chain. Switch the unit first, then type.
18K between 14K and 22K
14K is 58.3% gold. 22K is 91.7% gold. For one gram of jewelry, 18K contains 18/14 as much pure gold as 14K, about 29% more, and 18/22 as much as 22K, about 18% less. The color usually follows: 18K yellow is richer than 14K yellow and a step less saturated than 22K. The wear goes the other way. 14K is the tougher daily metal. 22K is the one that shows a dent.
| Karat | Percent | Stamp | Pure gold in 10 g |
|---|---|---|---|
| 14K | 58.3% | 585 | 5.83 g |
| 18K | 75% | 750 | 7.50 g |
| 22K | 91.7% | 916 | 9.17 g |
Ten grams of 18K is exactly 7.50 grams of pure gold, because the purity is exactly three quarters. The 22K figure is 10 × 22 ÷ 24, which is 9.17 grams. Price those pure grams with the calculator when you want money. This table stays in grams so it is still true after the gold price moves.
A new 18K ring’s shop price includes the making and the margin, so it sits above melt. A recognized 18K watch can sit even further above melt because people buy the watch, not the gold. Scrap ignores both premiums. If you are melting a broken chain, use melt. If you are selling a working watch with its papers, melt is the floor under a different market, not the answer. 24K is the page for pure bullion, where the premium question comes up in its purest form.
18K Gold Calculator questions
Is 18K better than 14K?
It contains more gold, 75% instead of 58.3%, and the color is richer. It is also softer, so it scratches sooner. “Better” depends on whether you want color and gold content or a harder metal for daily wear. Per gram of jewelry, 18K melt is 18/14 of 14K melt, about 29% more. Per gram of pure gold, they are the same metal.
What does a 750 stamp mean?
750 means 750 parts gold per thousand, which is exactly 75%. That is the same as 18 divided by 24. Unlike 14K and 585, the 18K stamp and the formula agree. A piece stamped 750 belongs on this page. A piece stamped 18K belongs here too.
Are solid gold watch cases 18K?
Many of them are, and they are stamped 750 or 18K on the case. The movement, the dial, the crystal and the strap are not gold. Weigh the case if you can separate it, or ask a buyer to weigh the gold parts only. Pricing the whole watch at 18K would count steel and leather as gold.
Is white gold stamped 18K still 75% gold?
Yes, if the stamp says 18K or 750. The white color comes from the alloy, often nickel, palladium or other white metals, and the surface is often rhodium plated. Rhodium wears off and the metal underneath looks warmer. The plating is too thin to add meaningful gold weight. The 75% figure is the gold in the alloy, not the plating.
Why does 18K scratch more easily than 14K?
More of the alloy is gold, and gold is a soft metal. The copper, silver and other metals in 14K are what make that alloy harder. An 18K ring can still last for decades. It will just show fine scratches sooner, and a very thin shank is easier to bend. None of that changes the melt math.
How much more is 18K than 14K for the same weight?
Multiply the 14K melt by 18/14, which is about 1.29. The same weight of 22K is 22/18 of the 18K melt, about 22% more. The worked example on this page applies those ratios to one piece at the current price, so you can see the gap in money rather than only as a percent.