24K↔
Two-Way Gold Conversion
Exact karat mass-balance conversion.
Conversion Result
—
—
Input Weight—
Karat—
Fine Gold—
Karat Gold—
Non-Gold Alloy—
Gold Fraction—
The Conversion Formula
Karat Gold Weight = Pure Gold Weight ÷ (Karat ÷ 24)
Fine Gold = Karat Gold Weight × (Karat ÷ 24)
Non-Gold Alloy = Karat Gold Weight − Fine Gold
Fine Gold = Karat Gold Weight × (Karat ÷ 24)
Non-Gold Alloy = Karat Gold Weight − Fine Gold
Example: Pure Gold to 18K
If you have 10 g of pure gold and want the equivalent amount of 18K gold:
10 ÷ (18 ÷ 24) = 13.333333 g of 18K gold
The additional 3.333333 g represents the theoretical non-gold alloy portion.
Example: 20 g of 18K to Pure Gold
20 × 18 ÷ 24 = 15 g fine gold
That leaves 5 g of non-gold alloy.
The two directions are mathematical inverses when the same karat assumption
is used.
Important Limitations
This is a mass-balance conversion based on the standard karat relationship. It does not identify the specific metals contained in the alloy or account for manufacturing loss, solder, impurities or refining recovery.
Frequently Asked Questions
How do you convert pure gold to 18K gold?
Divide the pure-gold amount by 18/24.
How much pure gold is in 20 g of 18K?
15 g of fine gold.
How much 22K contains 10 g pure gold?
Approximately 10.9091 g.
Does this account for alloy chemistry?
No. It uses the karat relationship only.
Is 24K treated as pure gold?
Yes, for this calculation.