Troy Ounce to Grams Converter
| Troy oz | Grams | The metal |
|---|---|---|
| 1 | 31.1035 | the gold-standard coin |
| 0.0322 | 1 | the one-gram bar |
| 32.15 | 1000 | the kilobar |
| 400 | 12,441 | good-delivery brick |
A troy ounce is 31.1034768 grams - about ten percent heavier than the ordinary ounce - and it is the only ounce the precious-metals market has ever used: gold, silver, platinum and palladium all quote per troy ounce, spot prices included. Type either number and the converter lands the other.
The name comes from Troyes, the Champagne fair town whose weights medieval Europe trusted, and the system survives for one reason: a thousand years of gold accounting do not get re-based for convenience. The FAQs cover the ounce collision that bites every first-time buyer, and the pennyweight the jewelry trade still quotes.
How to use
- Type the troy ounces from a bullion listing or spot-price quote - grams appear instantly, or run the reverse.
- Read the table for the market's standard bars and coins, from the one-gram souvenir to the kilobar and the 400-ounce good-delivery brick.
- Jewelry math rides on pennyweights: one troy ounce is twenty of them, and scrap-gold buyers still price by the dwt.
Frequently asked questions
How many grams is a troy ounce?
Exactly 31.1034768 - a definition, not a measurement. The ordinary (avoirdupois) ounce is 28.3495 grams, so a troy ounce is about 9.7 percent heavier. If a gold coin weighs 31.1 grams it is a true troy ounce; if a food label says an ounce, it means the lighter one. Two ounces, one name, a nine percent gap - and precious metals always mean the heavier one.
Why is it called a troy ounce?
From Troyes in Champagne, France - the great medieval fair city whose standardized weights traders trusted across borders, the way the pound sterling once meant an actual pound of silver. The weight system was English codified in the fifteenth century and has governed precious metals ever since. The city gave the unit its name; the gold market gave it immortality.
What is a pennyweight?
One twenty-fourth of a troy ounce - 1.5552 grams, abbreviated dwt (d for denarius, the old penny). Jewelers and scrap-gold buyers quote in pennyweights because rings and chains weigh a handful of them, and the arithmetic is old: twenty pennyweights to the ounce, twenty-four grains to the pennyweight. When a buyer prices your gold per dwt, this converter translates to grams instantly.
Why does silver trade in the same ounce as gold?
One market, one ruler: gold and silver have traded against each other for millennia, and a single weight unit keeps the gold-silver ratio honest. The spot prices you see quoted per ounce are both troy, so the ratio arithmetic - silver at 31, gold at 2,600 means roughly an 84-to-1 ratio - works without conversion. Mixing in avoirdupois ounces would quietly corrupt every historical comparison.
How much is a kilobar in troy ounces?
The 1-kilogram bar is 32.15 troy ounces; the 400-ounce good-delivery brick that central banks vault is about 12.4 kilograms. The table runs the standard sizes - the troy ounce is the accounting unit, but the metal physically moves in kilos and bricks whose gram weights are decimal, which is exactly why both columns matter when reading a dealer's invoice.