Room for ChanceWhat it measures and where it is used
This tool converts mass, the quantity expressed in kilograms, grams or pounds. Weight is a force and is measured in newtons, even though everyday speech often calls mass weight. In 2019 the kilogram’s definition moved from a physical prototype to the Planck constant. Troy and ordinary ounces differ.
- Classification
- SI base quantity
- SI unit
- kg
- Dimension
- M
L: length; M: mass; T: time; Θ: temperature; N: amount of substance. The dimension symbol N is not the unit symbol for newton.
How it works
The calculation first converts to a common reference unit, then to the destination unit. Factors in the table show the reference value for one unit.
Example
1 lb ≈ 0.45359237 kg
Available units
Reference unit: kg
| Available units | Reference factor |
|---|---|
| kg | 1 × x |
| g | 0.001 × x |
| mg | 0.000001 × x |
| µg | 0.000000001 × x |
| t | 1,000 × x |
| lb | 0.45359237 × x |
| oz | 0.028349523125 × x |
| st | 6.35029318 × x |
| ct | 0.0002 × x |
| oz t | 0.0311034768 × x |
| ton (US) | 907.18474 × x |
| ton (UK) | 1,016.0469088 × x |
Units, history and conventions
The International System of Units (SI) received its name in 1960. Since the 2019 revision, its definitions use fixed values of seven defining constants. SI base and derived quantities should not be confused with the different units used to express them.