Last updated: October 6, 2026
Editorial responsibility: Best Top 10 Gold Investments · Sources checked October 6, 2026.
To estimate gold’s metal value per gram, divide your USD price per troy ounce by 31.1034768. For an item, multiply that result by its gross weight in grams and its gold-purity fraction.
No live quote is supplied. Enter a dated reference price from your chosen source. A one-gram bar’s retail price also reflects the product and transaction costs, so the calculated metal value is not a price at which you can necessarily buy or sell.
Calculate gold value per gram
Enter your own USD price per troy ounce. No market price is supplied or fetched. The calculation stays in this page and does not submit a quote request.
The formula, with units
Metal value (USD) = reference (USD/troy oz) ÷ 31.1034768 (grams/troy oz) × gross grams × purity ÷ 100.
NIST’s unit tables distinguish the troy ounce used for precious metals from the ordinary ounce. The calculator uses 31.1034768 grams per troy ounce. If the product specification already states fine-gold weight, use that weight with 100% purity to avoid applying purity twice.
A one-gram example you can reproduce
Hypothetical inputs: $3,000 per troy ounce, 1 gram gross weight and 99.99% purity. These yield approximately $96.45 per pure-gold gram and $96.44 of metal value in the item.
If the complete purchase quote is $115, the difference is approximately $18.56, or 19.24% above the unrounded metal value. Calculations use unrounded intermediate values; displayed dollars are rounded to cents.
A high percentage difference can matter even when the dollar difference looks small. This example explains arithmetic only. It does not define a fair premium, recommend a purchase or supply today’s gold price.
Read purity correctly
| Product notation | Entry in the purity field | Scope |
|---|---|---|
| 999.9 fine | 99.99 | Use the actual product specification. |
| 999 fine | 99.9 | Fineness is parts per thousand. |
| 18 karat | 75 | Nominal gold fraction: 18 ÷ 24. |
| 14 karat | 58.333333 | Nominal 14 ÷ 24; use a stated or measured fineness when available. |
A hallmark is not an assay performed by this website. For jewelry, gross weight can include stones or other non-gold parts, and a resale offer may include testing, refining and other deductions. The calculator does not authenticate a product or value its craftsmanship.
Why the purchase quote differs
The calculator’s optional quote field compares what you enter with metal reference value. Include the charges you want to compare, consistently across offers. A negative difference means the entered quote is below the reference; it does not establish that an offer is genuine.
Use the complete-quote example for shipping and payment costs. For a purchase channel, read where to buy gold. IRA account charges belong in the separate fee worksheet.
Sources and editorial scope
Sources checked October 6, 2026. Calculations and comparisons are educational. Hypothetical figures are not current market prices, provider quotes or investment forecasts.