Gold Weight Converter

Gold and precious metals use the troy weight system, not the everyday avoirdupois system.

Base unit: grams

Troy system:

• 1 troy ounce = 31.1035 grams
• 1 pennyweight (dwt) = 1.55517 grams = 1/20 troy ounce
• 1 troy pound = 373.242 grams = 12 troy ounces
• 1 grain = 0.06480 grams
• 1 troy ounce = 480 grains = 20 pennyweight

Regional gold units:

• 1 tola (India) = 11.6638 grams = 3/8 troy ounce
• 1 baht (Thailand) = 15.244 grams
• 1 mesghal (Iran) = 4.6083 grams
• 1 tael (Hong Kong) = 37.429 grams

Troy vs. avoirdupois:

• 1 troy ounce = 31.103 g (heavier)
• 1 regular ounce = 28.350 g (lighter)

When gold prices are quoted “per ounce,” it always means troy ounces.

Troy weight is the source of a famous riddle: which weighs more, a pound of gold or a pound of feathers? The feathers, because gold is weighed in troy pounds (12 troy ounces, about 373 grams) while feathers use the everyday avoirdupois pound (16 ounces, about 454 grams). Yet a troy ounce is heavier than a regular ounce, 31.1 grams versus 28.35, so a troy ounce of gold beats a regular ounce of feathers. The two systems simply don’t line up, which is exactly why precious metals get their own.

When gold is quoted “per ounce,” it always means the troy ounce, and the same holds for silver and platinum. Don’t confuse weight with purity, either: karat measures how pure the gold is (24k is pure, 18k is 75%), not how much it weighs. A heavy 14k chain can contain less actual gold than a lighter 22k one, so for value you need both the weight and the karat.