Gold Value Calculator (Grams)
Estimate the melt value of your gold jewelry, coins, or scrap by weight in grams and purity in karats.
How this gold calculator in grams works
This tool estimates the value of gold based on three core inputs: weight in grams, purity (karat), and market price. If you only know gold price per ounce, the calculator converts it into price per gram automatically.
- Weight: total mass of your item in grams.
- Purity: gold content expressed in karats (24K is pure gold).
- Price: current 24K market price per gram (directly or via ounce conversion).
Formula used in the calculator
The calculation follows this sequence:
- Purity fraction = Karat / 24
- Pure gold grams = Total grams × Purity fraction
- 24K price per gram = Spot price per ounce / 31.1034768
- Gross value = Pure gold grams × 24K price per gram
- Estimated payout = Gross value × (Buyer payout % / 100)
Quick karat reference
Common purities
- 24K = 99.9% gold
- 22K = 91.7% gold
- 18K = 75.0% gold
- 14K = 58.5% gold
- 10K = 41.7% gold
- 9K = 37.5% gold
Example: 18K ring value in grams
Suppose your ring weighs 12 grams, purity is 18K, and spot gold is $2,050/oz.
- Price per gram (24K) ≈ 2050 / 31.1034768 = $65.91
- Pure gold grams = 12 × (18/24) = 9 grams
- Gross melt value ≈ 9 × 65.91 = $593.19
If a buyer pays 90% of melt value, your estimated offer would be about $533.87.
Tips for more accurate estimates
1) Weigh carefully
Use a digital jewelry scale with at least 0.01g precision for small items.
2) Verify purity markings
Hallmarks help, but testing (acid, XRF, or professional appraisal) provides better certainty, especially for old or mixed-metal pieces.
3) Compare multiple buyers
Payout rates vary. Pawn shops, refiners, and gold buyers may all offer different percentages of melt value.
4) Track live gold prices
Spot prices change throughout the day. A quote from this morning may not match an afternoon offer.
Frequently asked questions
Is gram-based calculation better than ounce-based for jewelry?
Yes. Most jewelry pieces are measured in grams, so gram-based valuation is usually more practical.
Does this include gemstones or craftsmanship value?
No. This calculator estimates metal value only. Designer pieces or gemstone jewelry can be worth much more than melt value.
Why is my offer lower than calculated value?
Buyers include refining costs, business margin, and risk. That is why real-world offers are typically below theoretical melt value.