AI Calculator
Generated on demand with DeepSeek AI
Gold Price Calculator.
Estimate the value of a gold item from its weight, purity, and the current spot price per troy ounce, including a dealer premium or discount.
Your inputs
How it works
- 1
Enter the item weight in grams and choose its purity (karat or fine-gold millesimal).
- 2
Enter the current gold spot price per troy ounce and any dealer premium or discount.
- 3
Convert ounces to grams using 31.1034768 g per troy ounce.
- 4
Multiply by the purity fraction and the premium factor to get the estimated value.
weight_grams * (spot_price / 31.1034768) * (purity == '24k' ? 0.999 : purity == '22k' ? 0.917 : purity == '18k' ? 0.75 : purity == '14k' ? 0.583 : purity == '10k' ? 0.417 : purity == '999' ? 0.999 : 0.916) * (1 + premium_percent / 100)Frequently asked questions
Why is the value lower than the spot price times weight?
Jewelry is rarely pure gold. An 18K item is only 75% gold, so only that fraction is valued at the fine-gold spot price.
What is a dealer premium?
A markup over melt value for fabrication, design, or retail margin. Enter 0 for scrap or melt value, or a negative number for a buy-back discount.
How many grams are in a troy ounce?
One troy ounce equals 31.1034768 grams, which is heavier than the 28.35 g avoirdupois ounce used for food.
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Results
Formula checkedAI-generated estimate for general guidance only — not professional advice.
How it works
Estimate the value of a gold item from its weight, purity, and the current spot price per troy ounce, including a dealer premium or discount.
- Enter the item weight in grams and choose its purity (karat or fine-gold millesimal).
- Enter the current gold spot price per troy ounce and any dealer premium or discount.
- Convert ounces to grams using 31.1034768 g per troy ounce.
- Multiply by the purity fraction and the premium factor to get the estimated value.
Formulas
The math behind this calculator, written out so you can verify the result.
Melt value
Convert the item weight to troy ounces, multiply by the spot price, then scale by the fraction of fine gold.
Example:
Input: 10 g of 18K at $2,400/oz
Calculation: 10 ÷ 31.1034768 × 2400 × 0.75
Result: ≈ $578.71
With dealer premium
A positive premium raises the price above melt; a negative value models a dealer buy-back discount.
Example:
Input: Melt $578.71, premium 5%
Calculation: 578.71 × 1.05
Result: ≈ $607.65
Real-world use cases
Where this calculation shows up in everyday life.
Scrap gold valuation
Estimate what a jeweler or refiner might pay for old chains, rings, or coins based on melt value.
Example: 12 g of 14K at $2,300/oz with a 10% buy-back discount.
Comparing jewelry prices
Check whether a retail price is close to melt value or carries a large fabrication premium.
Example: An 18K bracelet quoted at $900 versus a melt value of $580.
Coin and bar checks
Value bullion coins and small bars by fine-gold content rather than total weight.
Example: A 1 oz 999 coin at spot plus a 4% premium.
Tips and common mistakes
Tips
- Use the live spot price for the day you are valuing the item; gold moves daily.
- Karat purity is approximate — assay results can differ slightly from the nominal fraction.
- For coins, use the stated fine-gold weight rather than the total coin weight.
- Remember that stones and non-gold parts add weight but no melt value.
Common Mistakes to Avoid
- Using a regular 28.35 g ounce instead of the 31.1034768 g troy ounce.
- Treating the karat number as a percentage (18K is 75%, not 18%).
- Forgetting that dealer premiums and buy-back discounts move the price away from melt value.