An 18-karat gold piece isn't pure gold — it contains exactly 75% gold. This single figure explains almost everything you need to know before selling. Yet many sellers overlook it and reason as if their ring were worth the equivalent of pure gold. The result: they expect an amount that never existed, or worse, they're convinced their gold "isn't worth much".
| Karat | Purity | Price per gram (spot, USD) | Jayma Or buy-back price |
|---|---|---|---|
| … | |||
The truth is simpler and more reassuring: 18-karat gold is one of the most common in jewelry, and its resale value is calculated down to the gram, no mystery about it. You just need to know the right method.
At Jayma Or, we buy back 18-karat gold jewelry in Dakar every day — rings, chains, bracelets, earrings. We test and weigh in front of you, we explain the price based on the world market rate, and we pay cash the same day. Here's everything you need to understand about the 75%.
In this guide, you'll discover:
- what "18 karat = 75%" actually means;
- how the resale value of your 18K gold is calculated;
- how to recognize a genuine 18-karat piece;
- the calculation mistake that costs you money.
18 karat = 75% gold: what it means
The karat measures the purity of gold in an alloy. Out of 1,000 parts of metal, an 18-karat piece contains 750 of pure gold — that is, 75%. The remaining quarter is made up of other metals (copper, silver…) added to give the piece strength and color. That's why you find the hallmark "750" or "18K" on these pieces.
To place 18 karat relative to the other purities:
- 24 karat: 99.9% gold (pure gold, too soft for most jewelry).
- 21 karat: 87.5% gold, highly prized in the region.
- 18 karat: 75% gold, the great classic of fine jewelry.
- 14 karat: 58.3% gold, more economical.
Direct consequence: at equal weight, an 18K piece is worth less than a 21K, but more than a 14K. It's logical, since it contains more gold than one and less than the other. To dig deeper, see our article on the different types of gold.
How the resale value of your 18K gold is calculated
The calculation comes down to three variables:
- The exact weight of the piece, measured to the gram and the tenth of a gram.
- The purity, which is 75% for 18 karat.
- The day's rate for the gram of gold, which changes daily according to the world market.
The formula: weight × 75% × the day's price per gram of fine gold = the value of your piece. The 18K buyback price displayed on our home page already builds in this purity calculation: you read the price per gram for 18 karat directly. It's your most reliable benchmark; check the day's rate before any sale.
The calculation mistake that costs you money
The most common mistake? Forgetting the 75% factor. Some sellers take the rate for pure gold, multiply it by the total weight of their 18K piece, and get an inflated amount that later disappoints them. Conversely, some unscrupulous buyers play on this confusion to make it seem like "18-karat gold is worth almost nothing".
The right approach: never reason about pure gold for an 18-karat piece. Always reason about the 75%. An honest buyer applies exactly this coefficient — no more, no less — and explains it to you.
How to recognize a genuine 18-karat piece
Before selling, identify what you actually have in your hands:
- Look for the hallmark: "750", "18K", or "18 ct", often engraved inside a ring band or on the clasp.
- Beware of gold plating. A piece that's merely plated sometimes carries the marking "GP" or "plated": it contains only a thin layer of gold and doesn't have the same value.
- When in doubt, have it tested. A precise test removes any ambiguity about the real karat. Discover the methods for checking gold purity.
The testing and weighing should always be done in front of you: it's the golden rule of a transparent sale.
Frequently Asked Questions
Is 18-karat gold worth less than 21-karat gold?
At equal weight, yes: 18K contains 75% gold versus 87.5% for 21K. It is worth more, however, than 14-karat gold (58.3%).
My 18-karat piece is broken, can I sell it?
Yes. Broken, bent, or mismatched, it's worth exactly the gold it contains. Its condition takes nothing away from the value of the metal.
How do I know if my piece is really 18 karat?
Look for the hallmark "750" or "18K". If in doubt, a quick, non-destructive test determines the real karat precisely.
Does the price of my 18K gold change every day?
Yes, because it follows the world market rate for gold, which changes daily. Check the day's rate displayed on our home page before selling.
Do you accept karats other than 18?
Of course: we buy back 21K, 18K, and 14K, as well as broken gold, scrap, coins, and bars.
Take action: get your 18-karat gold appraised
You now understand what your 75% gold is really worth, how the calculation is done, and how to avoid the costly mistake. All that's left is to find out the exact amount for your jewelry.
Free, no-obligation estimate: send a photo of your 18-karat jewelry via WhatsApp to +221 78 111 66 87, or book an appointment. We test, weigh, and pay cash the same day — with travel to you available.
Before coming in, compare your estimate to the day's rate: in a few minutes you'll know what your 18-karat gold jewelry is really worth.