Karat Calculator
Gold Alloy Mix Calculator
Calculate exactly how much pure gold (24K) and base metal to mix to produce a target karat (22K, 18K, 14K, etc.) for a given weight.
💎 Gold Alloy Mix Calculator
Assumes base metal has zero gold content (copper/silver alloy).
- Pure gold (24K) needed
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- Base metal needed
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- Total alloy weight
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Frequently Asked Questions
How do I make 18K gold from pure gold?+
To make 10g of 18K gold: multiply 10 × (18÷24) = 7.5g of pure gold (24K) + 2.5g of base metal (typically copper/silver). The calculator above gives exact amounts for any weight and karat.
What base metals are mixed with gold?+
Common alloying metals: copper (rose gold, adds warm hue, most common), silver (white or green gold), palladium or nickel (white gold). Each affects colour, hardness, and tarnish resistance.
How do I make 22K gold?+
To make 10g of 22K: use 9.167g of pure gold + 0.833g of base metal.
Why is pure 24K gold not used for jewellery?+
Pure 24K gold is too soft — it scratches and dents easily. Alloying adds hardness. Most jewellery standards use 18K or 22K for the right balance of purity and durability.
What is rose gold?+
Rose gold is a gold-copper alloy. A common recipe for 18K rose gold: 75% pure gold + 22.25% copper + 2.75% silver. The higher the copper content, the deeper the rose colour.