Troy Ounces vs Grams: Precious Metals Weights Explained

Precious metals are weighed differently from groceries, and the units trip up plenty of new buyers. Getting them right matters, because spot prices are quoted per troy ounce and a small conversion error can distort what you think your stack is worth.

The troy ounce

Gold, silver, platinum and palladium are priced per troy ounce. A troy ounce is about 31.103 grams — heavier than the standard (avoirdupois) ounce of roughly 28.35 grams used for everyday items. So when a spot price says “per ounce,” it always means the troy ounce.

Grams and kilos

Smaller bars and coins are often sold in grams, while larger investment bars come in kilos. One kilogram equals 1,000 grams, or about 32.15 troy ounces. Being able to convert between these lets you compare prices across products of different sizes.

• 1 troy ounce ≈ 31.103 grams
• 1 kilogram = 1,000 grams ≈ 32.15 troy ounces
• A troy ounce is heavier than a standard ounce
• Spot prices are always quoted per troy ounce

Let your tracker do the maths

Rather than converting by hand, a good portfolio tracker handles the units for you. BullionTally shows values per gram, per troy ounce and per kilo, and revalues your holdings automatically at the live spot price — so you never have to worry about mixing up your ounces.