Gold value per gram
These values use the same price and currency currently selected in the calculator.
Waiting for a price. You can also enter one manually.
| Purity | Gold content | USD / gram |
|---|
Metal content only. The 24K row uses the tool’s theoretical 100% convention.
What this gold value calculator estimates
The calculator estimates the value of the gold content in an item. You need its weight, the unit used by your scale, and either a karat or fineness hallmark. The calculation then applies the selected gold price per troy ounce.
It does not test the metal or price gemstones, workmanship, brand, age, or collectibility. Enter your gold’s weight and purity in the calculator whenever you want to update the estimate.
How to use this gold value calculator
- Enter the first item’s weight, choose its weight unit, and select the purity that matches its karat or hallmark.
- Use Add another item for a collection. Every item may have a different weight, unit, and purity, and the result shows each value plus the combined total.
- Select USD, EUR, GBP, CAD, AUD, or INR. The market quote, result, buyer offer, and per-gram table all use that currency.
- Keep Market price selected for a timestamped quote, or choose Enter manually to supply your own price per troy ounce.
- Optionally enter a buyer’s offer. The comparison shows the offer as a percentage of estimated melt value and the difference in the selected currency.
How gold value is calculated
The tool converts each item to grams and uses this formula without rounding intermediate values:
Estimated melt value = (weight in grams ÷ 31.1034768) × purity fraction × gold price per troy ounce
Checked example
For 10 grams of 18K gold at an example price of USD 2,400 per troy ounce, 18K uses a purity fraction of 18 ÷ 24, or 0.75:
(10 ÷ 31.1034768) × 0.75 × 2,400 = USD 578.71
That item contains an estimated 7.5 grams of pure gold and has an 18K value of about USD 57.87 per gram at the example price. With multiple items, the tool runs the same calculation for each one and adds the unrounded item values for the combined total. A buyer’s offer is shown separately because an offer is not the same thing as melt value.
Weight and purity
The calculator accepts grams, kilograms, pennyweights, regular ounces, and troy ounces. A regular ounce (oz) is 28.349523125 grams, while a troy ounce (ozt) is 31.1034768 grams. Gold market prices are quoted per troy ounce even when an item is weighed in another unit.
Karats are calculated as parts out of 24. Fineness hallmarks are read as parts out of 1,000, so a 585 hallmark is exactly 58.5% in this tool and is slightly different from 14K at 14 ÷ 24.
| Tool option | Purity used | Tool option | Purity used |
|---|---|---|---|
| 10K | 41.6667% | 417 | 41.7% |
| 14K | 58.3333% | 585 | 58.5% |
| 18K | 75% | 750 | 75% |
| 21K | 87.5% | 916 | 91.6% |
| 22K | 91.6667% | 999 | 99.9% |
| 24K | 100% theoretical |
A hallmark can be useful identification, but it is not a laboratory test. Using the full weight of a plated or gold-filled item would overstate its gold content.
Gold spot price and currencies
Market prices come from Gold API. The server requests XAU directly in the selected currency and uses the provider’s quote timestamp. The calculator result and gold-value-per-gram table display that same timestamp and price snapshot.
The tool does not convert a USD quote in the browser and does not apply a separate exchange rate. It requests a currency-specific gold quote from the provider, so there is no separate exchange-rate source or exchange-rate timestamp to display. Cached or stale quotes keep their original quote time and are labeled accordingly.
When you enter a manual price, that number is treated as the selected currency per troy ounce. The result and table update from it, but the page labels it as manual and does not invent a market date. Changing currency clears a manual price and buyer offer to prevent a number from being silently reused under a different currency.
What affects the amount a buyer offers
A buyer may account for testing, refining losses and fees, operating costs, price movement, and margin. Different buyers can therefore make different offers for the same metal content.
Some pieces may also have value beyond their gold content because of gemstones, workmanship, brand, age, condition, or collectibility. This calculator does not measure those factors and does not suggest a standard payout percentage.
Frequently asked questions
How is gold value per gram calculated?
The selected gold price per troy ounce is divided by 31.1034768, then multiplied by the purity fraction. The table above performs that calculation for each supported karat using the current calculator price.
Can I calculate several gold items together?
Yes. Add each item separately so it can keep its own weight, unit, and purity. The result lists every item and shows their combined estimated melt value.
Should I choose a karat or a hallmark?
Choose the marking you actually have. Karats use K ÷ 24, while hallmarks use the stated parts per thousand. For example, 14K is 58.3333…% and 585 is exactly 58.5% in the calculation.
What happens when I enter a manual gold price?
The manual number replaces the market quote for the result and per-gram table. It is interpreted as the selected currency per troy ounce and is clearly labeled without a market timestamp.
How do currencies work?
The tool requests a gold quote directly in USD, EUR, GBP, CAD, AUD, or INR. All displayed amounts then use that selected currency. Changing currency clears manual prices and buyer offers.
Is the result a guaranteed selling price?
No. It is an estimate of metal content based on the inputs and price shown. An actual offer or appraisal may be higher or lower and may consider factors the calculator cannot assess.