The kilogram (kg) is the base unit of mass in the International System of Units. Because its name already contains the prefix kilo (1,000), NIST notes that multiples and submultiples of mass are formed from the gram: the unit is written 1 mg, never 1 μkg.
Conversion
g = kg × 1000
lb = kg × 2.2046
kg = lb × 0.4535924
oz = kg × 35.274
Example
A person weighing 80 kg weighs 80 × 2.2046 = 176.4 pounds. A 2 kg bag is 2,000 g, or 2 × 35.274 = 70.5 ounces.
The kg to lbs calculator converts any weight, and the guides how many grams in a pound and how many milligrams in a gram have charts and worked examples. Grams to kg handles the metric step.
Common mistakes
A kilogram is a mass, and "weight" in everyday speech usually means the same thing. Do not confuse 1 kg = 2.2046 lb with 1 lb = 2.2046 kg; the second is backwards (1 lb is 0.4536 kg).