Method and sources
The formula
Melt value = weight in grams × gold content × price of pure gold per gram.
Gold content is the stamped fineness: 999, 916, 750, 585, 417 or 375 parts per thousand (the option “24K (24/24)” uses exactly 1). Price per gram = spot price per troy ounce ÷ 31.1034768.
Weight units: 1 troy ounce = 31.1034768 g; 1 ounce (avoirdupois, kitchen scale) = 28.349523125 g; 1 pennyweight = 1/20 troy ounce = 1.55517384 g.
Where the price comes from
Gold and silver spot prices in US dollars come from gold-api.com. Our server fetches the price and keeps it for up to five minutes, so your browser never contacts the price service directly. The source and the time of fetching are shown next to every result.
Other currencies are converted with the European Central Bank’s daily reference rates, delivered by Frankfurter. These rates are published once per working day, so the converted price can be slightly behind the dollar price.
If the price cannot be fetched, the calculator says so and shows no value. If the latest update failed but a price from the last 24 hours is available, it is shown with a clear warning and its time.
Limits
- Spot prices are for large bars traded between banks and dealers. Nobody buys scrap jewelry at spot.
- Stones, solder, springs and plating are not gold. Weigh the metal only if you can.
- The stamp is the maker’s claim. Testing can show a different content.