About 1 mithqal
The mithqal (مثقال) is the traditional Islamic unit for gold: the weight of a gold dinar, 4.25 g, which is why the zakat nisab of 20 mithqal is 85 g. Local markets use their own mithqal: Iraqi gold shops quote 21K gold per mithqal of 5 g, and Iran's mesghal (مثقال) is 4.608 g. This page uses 4.25 g; see the Iraqi mithqal (5 g of 21K) and the zakat calculator.
Prices on this page are the value of the metal at the international spot price. Shops and dealers add premiums, making charges and local taxes; buy-back prices are usually below spot.