Grams to Ounces Converter

The avoirdupois ounce (the default "oz" you see on food packaging, postal scales, and kitchen recipes in the US and UK) is exactly 28.349523125 g. The troy ounce, used worldwide for precious metals like gold, silver, platinum, and palladium, is exactly 31.1034768 g, about 9.7 percent heavier. The two share the name "ounce" but come from different historical weight systems and are not interchangeable. If you weigh 100 g of gold, that is 3.22 troy oz at the spot price, not 3.53 avoirdupois oz, and the difference is real money.

Troy weight is the surviving medieval coinage standard, named after the French town of Troyes, a major trade fair city in the 12th to 14th centuries. European mints needed a precise, internationally recognized unit for striking coins, and the troy system (12 troy oz to the troy pound, 480 grains to the troy oz) won out over the heavier avoirdupois system that merchants used for bulk goods. When the global bullion market formalized in London (LBMA) and New York (COMEX) in the 19th and 20th centuries, the troy ounce was already the bullion unit of record, so it stayed. Spot prices for gold, silver, platinum, and palladium are still quoted per troy ounce today.

Different systems, different definitions. The avoirdupois pound (1 lb = 16 oz = 453.59237 g) is the standard everyday pound in the US, used for body weight, food, and shipping, and the count of 16 traces back to medieval English wool trade. The troy pound (1 troy lb = 12 troy oz = 373.2417216 g) is the older coinage pound and is still occasionally used by jewelers and bullion refiners. Because the troy ounce is heavier but the troy pound contains fewer ounces, the troy pound is actually lighter than the avoirdupois pound by about 18 percent. The US officially abolished the troy pound as a trade unit in 1828, but the troy ounce stuck around because it is the bullion price unit.

Most home digital kitchen scales cover roughly 1 g to 5 kg (about 0.04 oz to 11 lb), with 1 g resolution. That range is wide enough for everything from a 2 g pinch of yeast to a 4 kg turkey, and the resolution is fine enough for baking ratios. For espresso and pastry work, a pocket-style scale with 0.1 g resolution and a 2 kg maximum is more useful, even though it cannot handle a roast. Anything heavier than 5 kg (a Thanksgiving turkey, a sack of flour, a tray of bricks) usually moves to a freight scale or postal scale with a 25 to 50 kg capacity and 5 g resolution.

Exactly 2.2046226218... pounds. The factor comes from the 1959 International Yard and Pound agreement, signed by the US, UK, Canada, Australia, New Zealand, and South Africa, which pinned 1 lb at exactly 0.45359237 kg. Taking the reciprocal gives 1 kg = 2.20462262 lb to 8 decimal places, which is enough precision for any practical use. The everyday shortcut "1 kg is about 2.2 lb" is off by less than a hundredth of a percent, so doubling the kg figure and adding 10 percent gets you within shipping-label accuracy without a calculator.