9K Gold Calculator: What 9 Karat (375) Gold Is Worth

9K, 9ct, 375: Three Labels for One Alloy

The three labels describe the same metal. "9K" is the American spelling of karat, "9ct" is the British spelling (carat), and 375 is the millesimal fineness: 375 parts of gold in every 1,000 parts of metal. Divide 9 by 24 and you get 0.375, so a search for "9 karat as a gold percentage" has a one-line answer: 37.5%.

The other 62.5% is alloy (commonly silver and copper), with the proportions set by the maker for color and hardness. That share does not count toward melt value. Refiners recover the gold and price the rest as near zero for a gold sale.

Here is where 9K sits among the karats you are likely to see side by side in a jewelry box:

For the full list, including stamps you will not meet on 9K, see the gold purity chart.

Dollar Value per Gram, Pennyweight and Ounce

To keep the arithmetic checkable, assume gold at $4,400 per troy ounce, which works out to $141.46 per gram of pure gold (4,400 ÷ 31.103). Treat these as illustrations. The calculator above uses the live price.

Multiply $141.46 by 0.375 and one gram of 9K holds $53.05 of gold.

The troy ounce row is simply $4,400 × 0.375. The standard ounce row exists only to show the trap: a kitchen scale reading in ounces under-reports gold weight by almost 10% compared with troy ounces, and the value falls with it. Weigh in grams, then convert.

Common weights, for a quick sense of scale: 5 g of 9K is worth $265.24 in melt, 10 g is $530.48, 20 g is $1,060.95 and 50 g is $2,652.38. A buyer pays a share of these figures, never the whole thing, which the bracelet example below works through.

The Rules Behind 9K in Britain and in the US

In the UK, 375 is the floor. The Hallmarking Act 1973, Schedule 2 lists six approved standards for gold: 375, 585, 750, 916, 990 and 999. Nothing below 375 can be hallmarked as gold, and the 1975 guidance from the Joint Committee of the Assay Offices of Great Britain states it directly: minimum fineness "for gold the standard of 375." That is why 9ct is so common in British jewelry. It is the cheapest grade that can still be legally sold as gold.

The US rule is different from what many people assume. There is a widespread belief that 10K is the American legal minimum and that 9K "isn't gold" in the US. The current FTC Jewelry Guides do not say that. 16 CFR §23.3(c)(1) says an item made throughout of a gold alloy may be described as gold if the correct karat comes immediately before the word, and its own examples include "9 Karat Gold" and "9 Kt. Gold." What the rule requires is accurate disclosure. Calling 9K just "gold" with no karat, or stamping it 10K, is the deceptive part.

The 10K threshold still appears in that regulation, but only for coatings. The gold layer on anything sold as gold filled, rolled gold plate or gold electroplate must be at least 10 karat. A 9K layer cannot be marketed under those names in the US.

One more American detail affects value. The same section points to the National Stamping Act's tolerances: an article stamped with a karat may assay up to 3 parts per thousand under its mark if it contains no solder, or 7 parts per thousand if the tested part contains solder. A soldered piece stamped 9K can therefore lawfully test at 368 rather than 375. On a 15-gram item at $141.46 per pure gram, that tolerance is worth $14.85.

How Far 9K Trails 10K, and Everything Above It

9K and 10K are only one karat apart, and on a scale they look and feel the same. The value difference is smaller than people fear and larger than they assume.

Per gram, 10K holds $58.95 of gold and 9K holds $53.05, a gap of $5.90 per gram ($9.17 per pennyweight). Put another way, 9K carries 90% of the gold that the same weight of 10K does: 0.375 ÷ 0.4167 = 0.900. If a buyer quotes the same per-gram price for both, one of the two quotes is wrong.

Further up, the gaps widen quickly:

• 9K vs 14K: 9K holds 64% of the gold in 14K. A gram is $53.05 against $82.51.
• 9K vs 18K: exactly half. 37.5% against 75%, or $53.05 against $106.10 a gram.
• 9K vs 24K: a gram of 9K holds a little over a third of what a gram of fine gold holds.

The practical point is sorting. A drawer with mixed 9ct, 10K and 14K pieces should be weighed in separate groups. If the pile goes onto the scale as one lump, the buyer gets to pick the karat, and they will not pick the highest one. The 10K gold calculator runs the neighboring tier, and the gold price calculator handles any other stamp you find.

Reading the Marks on a 9ct Piece

A full British hallmark is a set of separate marks, not a single stamp. Three are compulsory, as the Edinburgh Assay Office lists them:

1. Sponsor's mark: initials in a shield identifying who sent the piece for testing.
2. Fineness mark: for 9ct, the figures 375.
3. Assay office mark: under the Act, a leopard's head for London, an anchor for Birmingham, a rose for Sheffield or a castle for Edinburgh.

Optional marks may appear next to them. Schedule 2 allows a traditional crown beside any gold standard (375 included), and the date letter has been voluntary since 1999. Read the number and ignore the decoration, because the number is what goes into the calculator.

Why a gate bracelet carries one hallmark, not one per link

A bracelet is hallmarked as one article. The 1975 assay offices' note on chain bracelets treats the whole bracelet or necklet as the thing that must be marked, so the hallmark goes once, on a part capable of bearing it, such as the clasp or padlock. Bare links are not expected to be marked. Very fine chain can be exempt altogether if every link and jump ring is made of wire under 0.9 mm, the jump rings are under 5 mm across, and no other part could take a mark. Separately, Schedule 1 of the Act exempts a gold article whose total metal weight is under 1 gram.

Numbers that are not gold marks

The UK fineness marks are whole numbers from that list of six. A decimal stamped near the 375, such as 0.25, is not part of the gold standard and should not be read as one. On a stone-set ring, a separate figure like this can be a stone weight in carats, but ask the seller or a jeweler instead of guessing. Either way it does not change the gold math, because the 375 is the mark that sets purity. More stamps are explained in the gold hallmarks guide.

Worked Example: A 15-Gram 9ct Gate Bracelet

Take a classic British 9ct gate bracelet with a padlock clasp. It is hallmarked 375 on the padlock and weighs 15.0 grams on a 0.01 g scale. It has no stones, so all 15 grams are metal.

• Pure gold content: 15.0 × 0.375 = 5.625 g
• Melt value at $141.46/g: 5.625 × 141.46 = $795.71

That $795.71 is the most a buyer can pay and still break even on metal. Applying the site's usual payout ranges for different kinds of buyers:

Two checks are worth doing. First, if the bracelet were 10K at the same weight, its melt would be $884.20. A buyer who tells you a 9ct piece is worth "about the same as 10K" is either rounding loosely or generously, and you should ask which. Second, a gate bracelet is full of solder joints, so under the US tolerance it could test as low as 368 and still meet its mark. That is roughly $14.85 of the melt figure on this piece. It is not a scam, but it is a reason not to expect a buyer's assay to come in above 375.

Run your own weight through the calculator above, write the melt figure down, and compare offers against it. Then the basics: get several quotes and watch the item being weighed. For everything else gold-related, start at the gold calculator home page.

Frequently Asked Questions