What does “karat” mean?
Pure gold is very soft, so it is mixed with other metals such as copper and silver to make it harder and usable for jewellery. The karat tells you how many of every 24 parts are pure gold: 21K means 21 parts gold and 3 parts other metals, i.e. 21 ÷ 24 = 87.5% gold. That is why higher karats are more expensive and more yellow, and lower karats cheaper and harder.
Karats compared
| Karat | Gold content | Hallmark | Pure gold in 10 g | Typical use |
|---|---|---|---|---|
| 24K | 99.9% | 999 | about 10 g | Bars |
| 22K | 91.7% | 916 | 9.17 g | Jewellery in the Gulf and India, some coins |
| 21K | 87.5% | 875 | 8.75 g | Most jewellery in Egypt and the Gulf, the Egyptian gold pound |
| 18K | 75% | 750 | 7.5 g | Fine and Italian designs, diamond and stone settings |
| 14K | about 58.5% | 585 | 5.85 g | Uncommon in the region |
The Egyptian gold pound weighs 8 g of 21K gold, so it contains 7 g of pure gold.
The price difference
The price per gram follows the gold content. If 24K costs a hypothetical 5,000 per gram:
- 22K = 5,000 × 22 ÷ 24 ≈ 4,583
- 21K = 5,000 × 21 ÷ 24 = 4,375
- 18K = 5,000 × 18 ÷ 24 = 3,750
So a gram of 18K is about 14% cheaper than 21K, but it also contains that much less gold: the gold value is the same. The real difference in the final price comes from making charges, which vary by design and shop. Price any piece by karat, weight and making charge with the gold calculator.
Which karat should you buy?
- For saving or investing: bars (24K) or gold pounds (21K), because their making charges are much lower than jewellery, so you lose less when you sell.
- For daily wear: 18K or 21K. 18K is harder and less likely to scratch or bend — good for rings, thin chains and pieces with stones.
- For engagement gifts: 21K is the norm in Egypt and holds more value per gram.
- For white gold: usually 18K mixed with white metals — it is real gold, not another metal.
How to check a piece’s karat
- The hallmark: look for the stamped number: 875 for 21K, 750 for 18K, 916 for 22K, 999 for 24K.
- The invoice: ask for an invoice listing the karat, weight, price per gram and making charge separately.
- Bars: usually come in a sealed pack showing weight, purity and a serial number — keep it sealed.
If you sell: what do you get back?
When you sell, the shop usually pays only for the pure gold at its buying price; the making charge and tax you paid don’t come back. If you bought 10 g of 21K with a making charge of 200 per gram, those 2,000 are a cost you won’t recover. The lower the making charge, the better gold works as savings.
Zakat nisab in each karat
For most scholars the nisab for gold is 85 g of pure (24K) gold, which equals:
- 22K: about 92.73 g
- 21K: about 97.14 g
- 18K: about 113.33 g
Egypt’s Dar al-Ifta takes the nisab as 85 g of 21K gold, about 99.17 g of 18K. The zakat calculator lets you choose either view: calculate the zakat on your gold.
Frequently Asked Questions
Is 18K real gold?
Yes — it is 75% pure gold, with other metals added for strength. It costs less per gram because it contains less gold, not because it is “fake”.
Which sells better later: 21K or 18K?
The gold value is the same relative to purity. But 21K carries more gold per gram and is in higher demand in Egypt and the Gulf. What matters most when you sell is the making charge you paid, because it doesn’t come back.
Why isn’t much jewellery made in 24K?
It is very soft, so it scratches and bends easily with daily wear, which is why it is used mainly for bars and coins.
How do I convert the price of one karat to another?
Multiply the price per gram by the new karat and divide by the old one. For example, 21K at 4,375 per gram means 18K = 4,375 × 18 ÷ 21 = 3,750.
Sources
- Purity and hallmarks: the standard fineness marks used for gold jewellery (999, 916, 875, 750, 585).
- Zakat nisab: 85 g of pure gold for most scholars, and 85 g of 21K for Egypt’s Dar al-Ifta, as in the zakat calculator and our methodology.
- Every figure in this article is calculated directly from purity; prices are hypothetical, for illustration only.