Weight Converter

1 kilogram = 2.20462 pounds. To convert kg to lbs: multiply by 2.20462. To convert lbs to kg: divide by 2.20462 (or multiply by 0.453592). Quick approximation: 1 kg ≈ 2.2 lbs. Common conversions: 1 kg = 2.205 lbs. 5 kg = 11.02 lbs. 50 kg = 110.23 lbs. 70 kg = 154.32 lbs. 100 kg = 220.46 lbs. For body weight: many countries use kg (metric), while the US, UK (partially), and some others use stones and pounds. 70 kg = 11 stone 0 lbs. 80 kg = 12 stone 8.6 lbs.

A stone (st) = 14 pounds = 6.35029 kg. Used in the UK and Ireland for human body weight. Ireland and the UK officially adopted the metric system but stones remain culturally common for body weight. Example: a person who weighs 80 kg is "12 stone 8 pounds" (80 / 6.35029 = 12.598 stone → 12 stone + 0.598×14 = 12 stone 8.37 lbs). Stone is essentially unused in North America, Australia, or mainland Europe. For reference: average male in UK: ~13 stone (82.5 kg / 182 lbs). NHS BMI calculators accept input in stones.

1 ounce (avoirdupois) = 28.3495 grams. 1 gram = 0.035274 ounces. Note: there are two different ounces! Avoirdupois ounce (oz): used for everyday weight (food, body weight). 16 oz = 1 pound. Troy ounce (ozt): used for precious metals (gold, silver). 12 troy oz = 1 troy pound. 1 troy oz = 31.1035 grams (heavier than regular oz). Always specify which when dealing with precious metals. Common food conversions: 1 oz ≈ 28g. 4 oz = 113g. 8 oz (half pound) = 227g. 16 oz (1 pound) = 454g. A standard US cup of water is 8 oz = 237ml (where water density ≈ 1 g/mL).

Mass: the amount of matter in an object — a fundamental property that doesn't change with location. Measured in kilograms, grams, pounds. Weight: the force of gravity on a mass — depends on gravitational field. Weight = mass × gravitational acceleration. On Earth's surface: 1 kg mass weighs ~9.81 Newtons. The confusion: everyday language uses "weight" to mean "mass." Your bathroom scale measures weight (force) but displays mass in kg or lbs, assuming Earth's standard gravity. On the Moon (1/6 gravity): a 70 kg person still has 70 kg mass but weighs only 114 N (vs 687 N on Earth). They'd feel 11.5 kg on a scale, but their mass is still 70 kg.

Three "tons" are commonly used: Metric ton (tonne, t): 1,000 kg = 2,204.62 lbs. Used internationally, in science, and global shipping. Short ton (US ton): 2,000 lbs = 907.185 kg. Used in the US for goods and materials. Long ton (UK ton, imperial ton): 2,240 lbs = 1,016.05 kg. Used in UK shipping and some industries. Conversions: 1 metric ton = 1.10231 short tons = 0.984207 long tons. In casual US conversation, "ton" usually means short ton. In international trade/science, "ton" usually means metric ton. Always specify when precision matters.