Unit Converters
Weight Unit Converter
Convert between kilograms, pounds, ounces, stone, metric tons, troy ounces, carats, and more. Instant bidirectional conversion - all calculations happen locally.
kg to lbs and lbs to kg
The kilogram (kg) and the pound (lb) are the two most commonly converted weight units. One kilogram equals approximately 2.20462 pounds; one pound equals approximately 0.453592 kilograms. These factors come from the international pound definition, adopted in 1959: 1 lb = 0.45359237 kg exactly.
Common weight conversions
| Value | Result |
|---|---|
| 1 kg | 2.20462 lb |
| 5 kg | 11.0231 lb |
| 10 kg | 22.0462 lb |
| 50 kg | 110.231 lb |
| 70 kg | 154.324 lb |
| 100 kg | 220.462 lb |
| 1 lb | 0.453592 kg |
| 5 lb | 2.26796 kg |
| 10 lb | 4.53592 kg |
| 100 lb | 45.3592 kg |
| 1 oz | 28.3495 g |
| 1 lb | 16 oz |
| 1 st | 14 lb (6.35029 kg) |
| 1 troy oz | 31.1035 g |
| 1 ct | 0.2 g |
| 1 metric ton | 1000 kg (2204.62 lb) |
| 1 short ton (US) | 2000 lb (907.185 kg) |
| 1 long ton (UK) | 2240 lb (1016.05 kg) |
The metric system: grams and kilograms
The metric system bases weight (more precisely, mass) on the gram. A kilogram is 1,000 grams; a metric ton is 1,000 kilograms. The kilogram is the SI base unit of mass and is defined in terms of the Planck constant since the 2019 redefinition of the International System of Units. For everyday purposes, a kilogram is very close to 2.2 pounds, making the quick mental estimate of "kilos × 2.2 = pounds" accurate to about 0.2%.
Imperial and US customary weight units
The imperial/US customary system uses ounces (oz), pounds (lb), stone (st), and tons. The relationships are: 16 oz = 1 lb, 14 lb = 1 stone, 2,000 lb = 1 short ton (US), 2,240 lb = 1 long ton (UK). Note that the US short ton and the British long ton are different. The stone is still commonly used for body weight in the UK and Ireland but is not used in the US.
Troy weight: gold, silver, and gemstones
Precious metals such as gold and silver are traded by the troy ounce (31.1035 g), which is heavier than the avoirdupois ounce (28.3495 g). The troy system originates from the medieval trade fair city of Troyes, France, and has been the international standard for bullion pricing for centuries. Spot prices for gold (XAU), silver (XAG), and platinum (XPT) are always quoted in US dollars per troy ounce.
Gemstones are measured in carats (ct), where 1 metric carat = 0.2 g exactly. A 1-carat diamond therefore weighs 200 milligrams. "Carat" as a weight unit should not be confused with "karat" (also written "carat" in UK English), which describes the purity of gold alloys (24-karat gold is pure; 18-karat is 75% gold).
Kitchen and baking context
Weight measurements (grams) are significantly more accurate than volume measurements (cups) for baking. One cup of all-purpose flour can weigh anywhere from 120 to 150 g depending on how it was scooped and packed. Professional pastry chefs universally use gram scales for this reason. If a recipe gives both volume and weight, always use the weight.
Body weight monitoring
Body weight fluctuates 1–3 kg throughout the day due to food, water, and clothing. For meaningful tracking, weigh yourself at the same time each day - ideally in the morning after using the bathroom and before eating. Weekly averages are more informative than day-to-day comparisons.
Scientific mass vs. weight note
In physics, mass (measured in kilograms) is an intrinsic property of matter, while weight is the force exerted on that mass by gravity (measured in Newtons: N = kg × m/s²). A 70 kg person weighs approximately 686 N on Earth and only about 115 N on the Moon (one-sixth the gravity). In everyday language, “weight” and “mass” are used interchangeably, but the distinction matters in science and engineering.