Quick answer: Gold value = grams × (karat ÷ 24) × the 24K price per gram: 10 g of 22K gold at 450 a gram for 24K is 10 × 22/24 × 450 = 4,125.
How it's calculated
Karat measures purity out of 24: 24K is pure gold (999), 22K is 22/24 = 91.7% (916), 21K is 87.5% (875) and 18K is 75% (750). If your price is for 24K, the price of a lower karat is the 24K price × karat ÷ 24. If the dealer quotes a price for your karat directly, choose "the karat above" and it is used as is.
Units: a troy ounce is exactly 31.1034768 g, the unit used for world gold prices. A tola is 180 grains, 11.6638 g; Gulf souqs sell bars in tola (the 10-tola bar is 116.64 g).
Gold prices change through the day. Enter the current price per gram from a dealer, your bank or your country's gold market; the World Gold Council publishes reference prices per ounce, which you can divide by 31.1035 to get the price per gram.
Paying zakat on gold? Use the zakat calculator.
Worked examples
- 10 g of 22K at 450 per gram (24K): 10 × 22/24 × 450 = 4,125.00
- 1 tola of 24K at 450: 11.6638 × 450 = 5,248.71
- 1 troy ounce of 24K at 450: 31.1035 × 450 = 13,996.56
Gold purity by karat
| Karat | Purity | Fineness |
|---|---|---|
| 24K | 99.9% | 999 |
| 22K | 91.7% | 916 |
| 21K | 87.5% | 875 |
| 18K | 75.0% | 750 |
Frequently asked questions
How do I calculate the price of 21K gold?
Multiply the 24K price per gram by 21 ÷ 24 (0.875). At 450 for 24K, 21K is 393.75 a gram.
How many grams is a tola?
11.6638 g. A 10-tola bar weighs 116.64 g.
How many grams is an ounce of gold?
Gold is weighed in troy ounces: 1 troy ounce = 31.1035 g, heavier than an ordinary ounce (28.35 g).
Why does the shop price differ?
Jewellery prices add a making charge, and buy-back prices are lower than the metal value. This calculator gives the metal value only.
What does 916 or 875 on gold mean?
It is purity in parts per thousand. 916 is 22K, 875 is 21K and 750 is 18K.
What if my price is for 22K and not 24K?
Set the karat to 22 and, under That price is for, choose The karat above. The price is then used as it is, with no purity adjustment.