Ounces to Pounds Converter

There are 16 ounces in a pound:

pounds = ounces ÷ 16

Sixteen, not ten and not twelve — the avoirdupois system that gave us the pound divided it into sixteen ounces, while the troy system used for precious metals divides its pound into twelve. A troy ounce is also heavier: 31.10 g against the avoirdupois 28.35 g. Gold quoted "per ounce" is per troy ounce, and using the wrong one misprices it by about 10%.

Everything on this page is avoirdupois, which is what food, post and body weight use.

The clean fractions are worth knowing:

• 4 oz = 0.25 lb (a quarter-pound)
• 8 oz = 0.5 lb (a half-pound, and a US cup of butter)
• 12 oz = 0.75 lb
• 16 oz = 1 lb
• 24 oz = 1.5 lb

Infant weights are the case where the mixed notation matters most. American birth weights are given as pounds-and-ounces — "7 lb 6 oz" — not as decimal pounds. That is 7 + 6/16 = 7.375 lb, or 3.345 kg. Reading it as 7.6 lb overstates the weight by 100 g, which is a meaningful error at that size.

Shipping rounds up to the next whole pound, so a 17 oz parcel (1.0625 lb) is billed as 2 lb. Trimming an ounce off a package that sits just over a boundary can halve the postage.

To convert back, multiply pounds by 16.