How many grams in an ounce of gold?

The ounce exchanges use to price gold is the troy ounce, exactly 31.1035 grams. When the news quotes "the gold price per ounce", it means about 31.1 grams of pure 24 karat gold.

Working out the gram price from the ounce price

1. Take the quoted price per ounce in dollars.
2. Divide by 31.1035 to get the price of one gram of 24 karat.
3. Multiply by the karat purity: 0.875 for 21 karat, 0.75 for 18 karat.
4. Convert into your currency.

Example: at 2,400 dollars an ounce, one gram of 24 karat is 2,400 ÷ 31.1035 ≈ 77.16 dollars, and one gram of 21 karat is 77.16 × 0.875 ≈ 67.52 dollars.

Why the jeweller's price differs

The figure here is the global raw gold price. A jeweller adds making charges, a margin and sometimes tax, so buying is dearer and selling back is cheaper.

The classical uqiyah is a different unit

In hadith and fiqh the uqiyah is forty dirhams of silver, about 119 grams. Sahih Muslim (979) reports: "There is no charity on less than five uqiyah", so the silver nisab of five uqiyah is 595 grams. Do not mix it up with the troy ounce.

From ounces to zakat

The gold nisab is 85 grams of pure gold, about 2.73 troy ounces. If your holding is close to that, continue to the gold zakat calculator.