What the calculation actually is
Zakat on gold and silver is arithmetic laid over a market price: 2.5% of the value of the metal held, once that value clears a minimum threshold called nisab. The rate itself — one fortieth — is agreed across schools of Islamic law and has been since the earliest sources on zakat; nothing about it is disputed or approximate.
Nisab is where the numbers get less tidy, and it is worth understanding why rather than just taking one figure on trust. The classical definition is 20 mithqal of gold or 200 dirhams of silver — units from a pre-modern coinage system. Converting a mithqal or a dirham to grams is where different reputable sources land on slightly different figures: gold nisab is published as 85 g by some major zakat organisations and 87.48 g by others, a difference of under 3%. This calculator uses 85 g and 595 g, the pair most commonly published, and says so rather than presenting either figure as beyond question.
Why the silver threshold almost always applies
Where someone holds both gold and silver — or gold alongside cash and other zakatable wealth — the majority position tests the total against whichever nisab is reached first, and in practice that is nearly always the silver threshold. Silver is worth a small fraction of gold per gram, so 595 g of it represents a far lower cash value than 85 g of gold does. Using the gold-only threshold when silver is also held would set the bar too high and understate who owes zakat, which is why this calculator always compares against the lower of the two.
A worked example makes the mechanism concrete. At a silver price where 595 g works out to roughly $535, and a gold price where 85 g works out to roughly $11,000, someone holding $2,000 of mixed gold and silver clears the silver nisab easily, even though the same $2,000 would sit well below the gold-only threshold. The correct comparison is the one that actually applies to what is held, not the more familiar of the two figures.
The one thing left genuinely open
Whether jewellery worn for ordinary personal use is zakatable at all is not a rounding difference the way the nisab gram conversion is — it is a real, long-standing disagreement between schools of Islamic law, and this calculator does not resolve it. The Hanafi position holds that gold jewellery is zakatable whether or not it is worn. The Maliki, Shafi’i and Hanbali schools generally treat jewellery kept for regular personal wear as exempt, reasoning that it functions like clothing rather than stored wealth. Both are held by serious scholarship, and which applies to a given piece of jewellery is a fiqh question, not a pricing one.
This tool prices the metal and applies the rate. It does not tell you whether the jewellery you are pricing is zakatable, and it does not check the one-lunar-year holding requirement, since that depends on a calendar rather than a market price. For a specific holding, that is a question for a scholar or a local zakat authority, in exactly the way this site defers to a qualified appraiser on anything a calculator cannot see.