Convert a gold price quoted per gram or kilogram into a troy-ounce price,
or enter a troy-ounce reference directly. Select a gold purity to calculate
a theoretical purity-adjusted price and optionally estimate the value of a
specific gold weight. This calculator uses the troy ounce used in precious
metals rather than the ordinary avoirdupois ounce.
What Is a Troy Ounce of Gold?
A troy ounce is the traditional weight unit used for precious metals.
Gold market quotations are commonly expressed in troy ounces, particularly
in international bullion markets.
One troy ounce is exactly defined as approximately 31.1034768 grams.
This makes it heavier than the ordinary avoirdupois ounce used for many
everyday products, which is approximately 28.3495 grams.
1 troy oz = 31.1034768 grams
The distinction is important. If a gold quotation says "per ounce," the
relevant precious-metals convention is normally the troy ounce. Using an
ordinary ounce in the calculation would produce an incorrect result.
How to Calculate Gold Price per Troy Ounce
The conversion depends on the unit of the reference price. When the
reference is quoted per gram, multiply it by the number of grams in one
troy ounce.
Price per troy oz = Price per gram × 31.1034768
When the reference is quoted per kilogram, divide the kilogram price by
the number of troy ounces contained in one kilogram.
Price per troy oz = Price per kg ÷ 32.1507466
If the reference is already quoted per troy ounce, no weight conversion is
necessary before applying an optional purity adjustment.
Gold Weight Conversion Reference
| Weight |
Grams |
Troy Ounces |
| 1 troy ounce |
31.1034768 g |
1 troy oz |
| 1 gram |
1 g |
0.0321507466 troy oz |
| 1 kilogram |
1,000 g |
32.1507466 troy oz |
| 10 troy ounces |
311.034768 g |
10 troy oz |
Gold Price per Troy Ounce by Purity
A market quotation often refers to high-purity gold. Jewellery and other
gold alloys can have lower karat grades. To create a basic purity-adjusted
comparison, the calculator applies the nominal karat fraction.
Purity-adjusted price per troy oz = 24K price × (Karat ÷ 24)
For example, 22K gold has a nominal gold fraction of 22/24, or approximately
91.67%. An 18K alloy has a nominal gold fraction of 75%.
| Karat |
Nominal Gold Fraction |
Price Factor |
| 24K | 100.00% | 1.0000 |
| 23K | 95.83% | 0.9583 |
| 22K | 91.67% | 0.9167 |
| 21K | 87.50% | 0.8750 |
| 20K | 83.33% | 0.8333 |
| 18K | 75.00% | 0.7500 |
| 14K | 58.33% | 0.5833 |
| 10K | 41.67% | 0.4167 |
| 9K | 37.50% | 0.3750 |
Troy Ounce vs Regular Ounce
The ordinary ounce and the troy ounce are different units. A regular
avoirdupois ounce is approximately 28.3495 grams, while a troy ounce is
approximately 31.1034768 grams.
| Unit |
Weight in Grams |
Common Use |
| Troy ounce |
31.1034768 g |
Precious metals |
| Avoirdupois ounce |
28.3495231 g |
General goods |
Always use troy ounces when calculating internationally quoted precious-metal
prices. Substituting ordinary ounces will produce a different and incorrect
gold price.
Gold Price per Troy Ounce and Physical Bullion
A calculated troy-ounce price represents a mathematical metal value based
on the reference price. The price of a physical gold coin or bar can differ
from this figure.
Dealer premiums
Physical bullion can carry fabrication, distribution, authentication
and dealer premiums above a market reference.
Dealer spreads
The price at which a dealer sells bullion can differ from the price
offered when buying it back.
Product characteristics
Coins and bars can have different premiums based on size, refinery,
mint, availability, demand and market conditions.
Using a Troy-Ounce Price for Gold Jewellery
A troy-ounce market reference can be converted into a theoretical value
for jewellery by accounting for the item's weight and purity. However,
jewellery pricing involves considerably more than the underlying gold
calculation.
Making charges, design, craftsmanship, stones, wastage policies, taxes,
retailer margins and brand premiums can all affect the final transaction
price.
Estimated metal value = Purity-adjusted price per troy oz × Troy-ounce weight
This makes the calculator useful as a reference point rather than a complete
jewellery appraisal.
Why Gold Prices Can Move
Gold prices can change as global financial markets react to interest rates,
currencies, inflation expectations, investment demand, central-bank activity,
geopolitical developments and broader economic conditions.
Consequently, a troy-ounce price entered into the calculator represents a
reference at a particular point in time. It should not be assumed to remain
fixed throughout the day.
Important Limitations
This calculator does not fetch or guarantee a live gold market quotation.
The result depends on the reference price entered by the user.
The karat calculation estimates nominal gold content mathematically. It
does not assay, authenticate or test physical gold.
Physical bullion and jewellery can trade at prices above or below theoretical
metal value because of premiums, discounts, fabrication costs, taxes,
workmanship, stones, dealer margins and other commercial factors.
Frequently Asked Questions
How many grams are in one troy ounce of gold?
One troy ounce equals approximately 31.1034768 grams.
How do I convert gold price per gram to price per troy ounce?
Multiply the price per gram by 31.1034768.
How do I convert gold price per kilogram to troy-ounce price?
Divide the kilogram price by approximately 32.1507466 troy ounces per kilogram.
Is a troy ounce the same as a regular ounce?
No. A troy ounce is approximately 31.1034768 grams, whereas an ordinary
avoirdupois ounce is approximately 28.3495 grams.
Does gold purity affect the troy-ounce price?
Yes. A purity-adjusted estimate depends on the selected karat's nominal gold
fraction.
Is this a live gold price calculator?
No. It converts the reference price you enter and does not guarantee a live
market price.
Why are precious metals quoted in troy ounces?
The troy ounce is a traditional precious-metals weight unit and is widely used
in international bullion markets.
Can I use this calculator for gold coins and bars?
Yes, it can estimate the theoretical metal value when the weight and purity
are known. Physical products may have premiums or discounts that are not
included in the calculation.