Raising gold karat: how much pure gold to add
Enter the weight and karat of your gold and the karat you want. You get the grams of 24K gold to add, the weight of the finished ingot and what that gold costs at today's price, in dollars or pesos.
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Raise karat calculator
The gold you add supplies the pure gold your metal is missing.
6.67 g
Melted with your 10.00 g of 14K, it makes 16.67 g of 18K gold.
- Final weight
- 16.67 g
- Pure gold in the ingot
- 12.50 g
- Cost of the gold you add
- USD 885.91
How to raise the karat of gold
- 1.Weigh the gold you want to raise and enter its karat.
- 2.Choose the karat you want to reach.
- 3.Choose the gold you will add: usually fine 24K, though 22K works too.
- 4.Check the grams to add and what they cost at today's price.
- 5.Melt everything together with borax and stir well before pouring.
The formula for raising karat
Raising the karat takes gold finer than the karat you are after. The pure gold in the final melt equals the pure gold you had plus the pure gold you add: weight × starting karat + added gold × its karat = final weight × final karat.
Solved for the added gold: the weight times the gap between the final and starting karat, divided by the gap between the added gold's karat and the final karat.
Example: 10 g of 14K raised to 18K with 24K gold: 10 × (18 − 14) ÷ (24 − 18) = 6.67 g of fine gold. The ingot weighs 16.67 g.
Raising karat is expensive because the only way is adding gold. With a lot of excess alloy, refining the metal is sometimes the better deal.
Frequently asked questions
How do I turn 10K gold into 14K?
With 24K gold: weight × (14 − 10) ÷ (24 − 14). For 10 g of 10K you add 4 g of fine gold and end with 14 g of 14K.
How much fine gold takes 14K to 18K?
Two thirds of your gold's weight: 10 × (18 − 14) ÷ (24 − 18) = 6.67 g for every 10 g of 14K.
Can I raise karat with 22K gold?
Yes, as long as the gold you add is finer than the karat you want. 22K can reach 18K, but takes more grams than 24K. Only gold above 22K can reach 22K.
Can karat be raised without adding gold?
Only by refining: separating the alloy chemically, with aqua regia for example, or sending it to a refiner. Melting without adding gold never raises the karat.
Is the price the one my supplier charges?
It is today's international gold price converted to dollars or pesos. Fine gold suppliers usually charge a little more; enter their price in the calculator to see your real cost.