Gold Purity Calculator
Convert between karat, millesimal fineness, and gold percentage, then calculate the pure gold weight and value of any jewelry piece.
Custom fineness:
Karat
—
Fineness
—
Gold %
—
$
Select a karat grade and enter the piece weight to see results.
Melt Value
18K$0.00
Estimated raw melt value at current spot price
Pure Gold Weight
0 g
0 ozt
Alloy Weight
0 g
0 ozt
Total Piece Weight
0 g
0 ozt
Price per Gram (pure)
$0.00
at entered spot price
Common Karat Reference
| Karat | Fineness | Gold % | Melt Value |
|---|
Melt value is calculated from the raw gold content only. Dealers typically pay 70–90% of melt value to cover refining and handling costs.
Summary
Convert between karat, millesimal fineness, and gold percentage, then calculate the pure gold weight and value of any jewelry piece.
How it works
- Select a karat grade or enter a custom millesimal fineness value.
- The tool computes the equivalent fineness, karat, and gold percentage automatically.
- Enter the total weight of your jewelry piece in grams or troy ounces.
- Enter the current gold spot price per troy ounce (or per gram).
- The calculator displays the pure gold weight and its estimated market value.
Use cases
- Determine how much pure gold is in a ring, necklace, or bracelet before selling.
- Compare the actual gold content of different karat grades side by side.
- Estimate the melt value of scrap gold at the current spot price.
- Verify the fineness stamp on jewelry against karat markings.
- Plan a gold purchase and understand exactly what purity you are buying.
- Convert between international purity systems used by different countries.
Frequently Asked Questions
Last updated: 2026-06-19 ·
Reviewed by Nham Vu