How we calculate gold prices
Last updated: November 8, 2026
This page explains where our figures come from and how we calculate them, so you can check every price yourself.
Worked example in the UK, with today's figures
For 9ct Gold (375): spot price US$4,059.82 per troy ounce ÷ 31.1035 × 0.375 × 0.7473 GBP per US dollar = £36.58 per gram.
Data sources
- Gold price: the international spot price for one troy ounce of gold in US dollars (XAU/USD). We collect it from several market data providers and compare them, so that a single faulty feed does not change the price.
- Exchange rates: current rates of each currency against the US dollar, used to convert the price into the local currency of each market.
Hallmarks and gold content
We calculate with the gold content stamped on the item. 585 gold contains 58.5 % gold, so we multiply by 0.585 rather than by 14/24 (58.33 %), because 585 is what the hallmark guarantees and what dealers pay for.
A troy ounce weighs 31.1035 grams. It is the unit used for gold everywhere and is about 10 % heavier than the ordinary ounce used for food.
Updates and data checks
Prices are updated throughout the day, and each page shows the time of the last update.
If the data for a market is more than 48 hours old, or the exchange rate for its currency is missing, we show no prices for that market rather than wrong ones.
Why dealer prices are different
Our prices show the value of the gold content alone. What you pay or receive at a dealer also includes: - the dealer's margin and costs, which is why buying prices are lower and selling prices higher; - making charges for jewellery; - VAT and other local taxes, where they apply; - premiums for coins and small bars.
No investment advice
All figures are for information only. Check the current price with your dealer or bank before you buy or sell.