Weight to Kilograms Converter
Free Weight kilograms Converter for human metrics units. Enter a value to see equivalent measurements across systems.
Formula
kg = lb x 0.45359237 | kg = oz x 0.028349523 | kg = st x 6.35029318 | kg = g / 1000
All conversions go through grams as the base unit. Each input unit has an exact conversion factor to grams. Kilograms are then derived by dividing grams by 1000. The pound to kilogram factor (0.45359237) is an exact definition established by international agreement.
Frequently Asked Questions
How do I convert pounds to kilograms?
Multiply the weight in pounds by 0.45359237 to get kilograms. This conversion factor is exact by definition: one pound avoirdupois equals exactly 0.45359237 kilograms. For a quick mental estimate, divide pounds by 2.2. So 150 pounds is approximately 150 / 2.2 = 68.18 kg (exact: 68.0389 kg). The inverse conversion multiplies kilograms by 2.20462262 to get pounds.
What is the difference between avoirdupois and troy weight systems?
The avoirdupois system is used for everyday weighing: 1 pound = 16 ounces = 453.59 grams. The troy system is used for precious metals: 1 troy pound = 12 troy ounces, where 1 troy ounce = 31.1035 grams. A troy ounce is heavier than an avoirdupois ounce, but a troy pound is lighter than an avoirdupois pound. When someone says an ounce of gold, they mean a troy ounce (31.1 g), not an avoirdupois ounce (28.35 g). This converter uses the avoirdupois system unless otherwise noted.
What is the difference between mass and weight?
Mass measures the amount of matter in an object (kilograms) and is constant everywhere. Weight is the gravitational force on that mass (newtons) and varies by location. On Earth, a 1 kg object weighs about 9.8 newtons. In everyday use, the terms are often used interchangeably.
How accurate are the results from Weight to Kilograms Converter?
All calculations use established mathematical formulas and are performed with high-precision arithmetic. Results are accurate to the precision shown. For critical decisions in finance, medicine, or engineering, always verify results with a qualified professional.
What formula does Weight to Kilograms Converter use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.