Kilograms to Ounces Converter

The kilogram is the SI base unit of mass, and every other metric mass unit is defined from it by powers of ten. One kilogram equals 1,000 grams exactly.

Kilograms are the everyday unit for body weight, market produce and cooking quantities, and they set luggage allowances and freight charges on shipping documents and airline tickets.

Conversions between kilograms, grams and tonnes are exact decimal shifts. Imperial factors are exact by definition, yet displayed results are rounded, so converting to pounds and back can change the last digit.

A common mistake is treating a stone figure as pounds. One stone is 14 pounds, so a reading of 12 stone is 168 pounds, not 12 pounds. For trade and medicine, kilograms are the safer unit because their subdivisions are decimal.

Because pounds carry a larger number for the same mass, a body-weight figure can look plausible in the wrong unit. Grams serve small cooking amounts, and tonnes serve freight, so the choice follows the size of the load.

An ounce is exactly 28.349523125 grams and one sixteenth of a pound, so sixteen ounces make one pound. That definition makes it the avoirdupois ounce, the unit used for ordinary trade.

Ounces appear on postal and courier weight bands, on food packaging and recipe cards, and in the jewellery trade, though precious metals are quoted in the troy ounce.

The gram and kilogram factors are exact decimal relations, and the imperial factors are exact by definition. Display rounding can still change the last digit on a round trip.

The usual error is confusing the troy ounce with the avoirdupois ounce: the troy ounce is 31.1035 grams, while the avoirdupois ounce is 28.349523125 grams. Ounces suit small parcels and portions, not bulk freight.

Ounces are most often confused with grams in recipes and postal weights, because the factor is 28.349523125 rather than a simple power of ten. Precious metals are quoted in the troy ounce, which is not the same as this ounce.