⚖️ Weight Converter
Switch between pounds, kilograms, grams, ounces, stones, milligrams, and metric tonnes.
Enter a value above to see the result
Common Weight Conversions
| Input | Unit | Result | Unit |
|---|---|---|---|
| 1 | Pound | 0.45359237 | Kilogram |
| 1 | Kilogram | 2.2046226 | Pound |
| 1 | Ounce | 28.349523 | Gram |
| 100 | Gram | 3.5273962 | Ounce |
| 1 | Stone | 6.3502932 | Kilogram |
| 70 | Kilogram | 154.32358 | Pound |
About Weight Conversions
Weight — more precisely, mass — is measured in everyday contexts using kilograms, grams, pounds, and ounces. The metric system, anchored to the kilogram, is the international standard and is used in science, medicine, and most countries worldwide. In 2019, the kilogram was redefined in terms of the Planck constant, making it one of the most precisely defined units in history.
The imperial system uses pounds (lb) and ounces (oz), with 16 ounces to the pound. The stone (14 pounds) is still used informally in the UK and Ireland for describing body weight. Metric tonnes (1,000 kg) are used for large quantities in shipping and international trade, while milligrams appear in pharmaceutical dosing.
Technically, weight and mass are not the same thing. Mass measures the amount of matter in an object and is constant regardless of location. Weight is the gravitational force acting on that mass — you would weigh less on the Moon but your mass would be unchanged. In everyday usage the terms are used interchangeably, which is acceptable for most practical purposes.
Frequently Asked Questions
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds. Conversely, one pound equals approximately 0.453592 kilograms. A quick rough estimate: multiply kilograms by 2.2 to get pounds.
How many ounces are in a pound?
There are exactly 16 avoirdupois ounces in one pound. This is the standard system for everyday goods in the United States. Note that troy ounces — used for precious metals like gold and silver — are slightly heavier (1 troy ounce ≈ 31.1 grams vs. 28.35 grams for avoirdupois).
What is a stone in pounds and kilograms?
One stone equals exactly 14 pounds, or approximately 6.35 kilograms. The stone remains in informal use in the UK and Ireland for expressing body weight. It is not recognized by the SI system.
How many grams are in an ounce?
One avoirdupois ounce equals approximately 28.3495 grams. For cooking, 28 grams is often used as a quick approximation. For precious metals using the troy system, one troy ounce equals approximately 31.1035 grams.
Is weight the same as mass?
In everyday language they are used interchangeably, but in physics they differ. Mass is the amount of matter in an object (constant everywhere) and is measured in kilograms. Weight is the gravitational force on that mass, measured in newtons. On the Moon, your mass stays the same but you weigh about one-sixth of what you do on Earth.
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All conversion results are provided for general informational purposes only. Our formulas use internationally recognized conversion factors; however, rounding may affect precision. Do not rely on these results for professional, medical, legal, or engineering decisions without independent verification. Read our full disclaimer.