Spot21K Gold Calculator
Estimate the melt value of 21K jewelry by weight, using a gold spot quote and the karat fraction.
Gold · $3,887.60 USD/ozt · $124.99 USD/gMarket quote · Gold API · 2026-11-14 14:09 UTC
Your item
100% Melt Value
8.75 g fine gold
- Estimated buyer payout · 80%
- $874.92
- Illustrative payout range · 70–100%
- $765.56 – $1,093.66
21K gold price by weight
| Weight | Melt value (USD) |
|---|---|
| 1 g | $109.37 |
| 5 g | $546.83 |
| 10 g | $1,093.66 |
| 20 g | $2,187.31 |
| 30 g | $3,280.97 |
| 40 g | $4,374.62 |
| 50 g | $5,468.28 |
| 100 g | $10,936.56 |
How to calculate melt value
Melt value = weight in grams × purity fraction × (USD spot price per ozt ÷ 31.1034768)
At 21K purity, 10 g contains 8.7500 g of fine gold. Use 31.1034768 g per troy ounce or 1.55517384 g per pennyweight.
Estimated payout = melt value × selected payout percentage.
Gold Hallmark & Stamp Guide
| Stamp | Karat | Gold content |
|---|---|---|
| 999 | 24K | 99.9% |
| 916 | 22K | 91.6% |
| 875 | 21K | 87.5% |
| 750 | 18K | 75.0% |
| 585 | 14K | 58.5% |
| 417 | 10K | 41.7% |
| 375 | 9K / 9ct | 37.5% |
Frequently asked questions
How pure is 21K gold?
21K is 21/24 gold by weight on the nominal karat scale.
What does a 875 mark mean?
It indicates approximately 875 parts gold per thousand. Confirm the alloy if the stamp is worn or the piece is plated.
How much fine gold is in a 21K bangle weighing 20 g?
20 × 21/24 gives 17.5 grams of fine gold, assuming the full weight is gold alloy.
Why does a dealer offer less than melt value?
A buyer may deduct refining, testing, shipping or operating costs. Ask for a written net offer with the tested purity and payable weight.
Should I weigh gemstones with the gold?
Use only the weight of the gold alloy. Stones, springs and other non-gold parts can overstate the result.