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Analyze Alloy Composition
Fine gold versus total non-gold alloy.
Composition Breakdown
—
—
Fine Gold
Non-Gold Alloy
Fine Gold Weight—
Fine Gold %—
Non-Gold Weight—
Alloy %—
Karat Fraction—
Total Weight—
The non-gold portion is a total mass, not an identification of the individual metals in the alloy.
Gold Alloy Composition Formula
Fine Gold % = Karat ÷ 24 × 100
Fine Gold Weight = Total Weight × Karat ÷ 24
Non-Gold Alloy Weight = Total Weight − Fine Gold Weight
Fine Gold Weight = Total Weight × Karat ÷ 24
Non-Gold Alloy Weight = Total Weight − Fine Gold Weight
Common Gold Alloy Compositions
| Karat | Fine Gold | Non-Gold Portion |
|---|---|---|
| 24K | 100% | 0% |
| 22K | 91.6667% | 8.3333% |
| 18K | 75% | 25% |
| 14K | 58.3333% | 41.6667% |
| 10K | 41.6667% | 58.3333% |
| 9K | 37.5% | 62.5% |
What “Alloy Percentage” Really Means
The alloy percentage is the portion of the material that is not counted as fine gold under the karat definition. It does not mean that every component metal has the same percentage.
For example, 18K means 25% total non-gold material by the standard karat
relationship. It does not mean 25% copper.
Example: 50 g of 22K Gold
Fine Gold = 50 × 22 ÷ 24
= 45.833333 g
Non-Gold Alloy = 50 − 45.833333
= 4.166667 g
= 45.833333 g
Non-Gold Alloy = 50 − 45.833333
= 4.166667 g
Important Limitations
This calculator provides a theoretical composition based on karat. Exact alloy chemistry requires the actual formulation or suitable analytical testing.
Frequently Asked Questions
What is gold alloy composition?
It describes the fine-gold and non-gold portions of the finished alloy.
How do you calculate gold alloy percentage?
Divide karat by 24 and multiply by 100.
What is the alloy percentage of 18K gold?
25% non-gold material by the standard karat relationship.
Does alloy percentage identify individual metals?
No. It only gives the total non-gold portion.
Can this calculate 24K composition?
Yes. The theoretical non-gold portion is zero.