FiLotPure Gold Calculator
Karat and fineness are two ways to write the same thing: how much of the piece is gold.
Your pieces
Optional. It gives the value of the gold.
Your result
Add a weight and a purity to see the result.
General information, not legal, tax or financial advice.
The numbers that travel together
- 24K is usually 999, close to pure gold
- 22K is 916, about 91.6 percent gold
- 18K is 750, 75 percent gold
A piece that is 22K is also 916. The two numbers mean the same purity, written on different scales. Divide the fineness by 10 to get the percentage: 916 is 91.6 percent gold, and 750 is 75 percent. A stamp in karats can be read as fineness, and a stamp in fineness can be read as karats, once the pairs are known.
The marks are rounded. 24K is 100 percent in theory and is stamped 999 in practice; 22K is 91.67 percent and is stamped 916.
Where to look
Look for a small stamp inside a ring, on a clasp, or on the back of a pendant. A stamp may state the purity. A stamp states it. It does not prove it. If there is no stamp, a jeweller can test the piece. Ask how they test it, and whether the test leaves a mark.
Pure grams
Weight times purity gives the pure grams: the part of the piece that is gold. 20 grams of 22K holds about 18.3 grams of pure gold. The rest of the weight is other metals. Those grams, times the price per gram, give the value of the gold in the piece at the world price. A buyer usually prices the gold in the piece, not the work.
To turn karats into a share: divide by 24. 18 divided by 24 is 0.75.
Where to go next
FiLot gives an AI assistant the gold price per gram in your currency.
How to add itFiLot keeps the record: what you have, what you paid. Sign in to add the photos of the papers you choose to keep.
Try the Beta