Weight Converter

Weight converter to convert common weight and mass units. Input a value in one of the fields below to instantly view the converted weight in the remaining fields.

US Tons:
UK Tons:
Metric Tons:

Scientifically speaking, this unit converter primarily focuses on mass conversion. However, for the sake of simplicity and common usage to avoid confusion, in this converter, the term "weight" is used when referring to relevant measurements. It's important to note that there is a distinction between mass and weight, which will be explained further in the following sections.

If you want to convert between all weight units, explore our comprehensive all weight units converter. It provides a wide range of weight units, allowing you to effortlessly convert between them with ease and accuracy.

If you require conversions between Imperial and Metric weight units without relying on a converter, you will need access to the appropriate conversion factors since they can be very difficult to remember. To obtain the necessary conversion factors, you may refer to the links provided at the end of this page. These links will direct you to reliable resources containing conversion factors, dedicated converters, conversion tables and comprehensive instructions on how to perform the conversions accurately.

Below, you will find information about Metric weight units and Imperial weight units, along with guidance on how to convert within each system.

Imperial and US Customary Mass Units:

In the Imperial and US Customary systems, the pound (lb) is the base unit of mass. All other units are either fractions or multiples of the pound.

The Imperial and US Customary systems share the same mass units, with the exception of the hundredweight (112 pounds in the Imperial system and 100 pounds in the US Customary system) and the ton (2240 pounds in the Imperial system and 2000 pounds in the US Customary system).

Converting weight units within the Imperial system involves understanding the conversion factors between different units.

To convert between Imperial weight units, you can follow these steps:

1. Identify the starting weight unit and the target unit for conversion.

2. Find the conversion factor between the two units. Conversion factors for common Imperial weight units are as follows:

  • 1 pound (lb) = 16 ounces (oz)
  • 1 stone (st) = 14 pounds (lb)
  • 1 US ton (T) = 2000 pounds (lb)
  • 1 UK ton (T) = 2240 pounds (lb)

3. To convert weight from one unit to another, multiply the given weight by the appropriate conversion factor. For example, to convert 10 pounds to ounces, you would multiply 10 by 16, resulting in 160 ounces.

Remember to consider the direction of the conversion. If you are converting from a smaller unit to a larger unit, divide the given weight by the conversion factor.

Similarly, You can use similar principles to convert between other Imperial weight units.

Metric Mass Units:

The Metric system is based on powers of 10 and uses standard prefixes that represent them, making it convenient to convert between different Metric units. These prefixes indicate multiples or submultiples of the base unit, making it easier to work with measurements that are either very large or very small. Here are some common Metric prefixes and their symbols:

  • Kilo (k): 1 kilo is equal to 1000 grams
  • Hecto (h): 1 hecto is equal to 100 grams
  • Deka (da): 1 deka is equal to 10 grams
  • Gram (g)
  • Deci (d): 1 deci is equal to 0.1 (1/10) gram
  • Centi (c): 1 centi is equal to 0.01 (1/100) gram
  • Milli (m): 1 milli is equal to 0.001 (1/1000) gram
  • Micro (μ) : 1 micro is equal to 0.000001 (1/1000000) gram
  • Nano (n) : 1 nano is equal to 0.000000001 (1/1000000000) gram

For each prefix, there is a specific conversion factor. To convert from a smaller unit to a larger unit, divide by the conversion factor and to convert from a larger unit to a smaller unit, multiply by the conversion factor.

For example to convert 500 grams (g) to kilograms (kg):

1. We know that 1 kilogram (kg) = 1000 grams (g) (since "kilo" means 1000)

2. To convert from grams to kilograms, divide the value in grams by 1000.

Therefore, 500 grams ÷ 1000 = 0.5 kilogram

Similarly, you can apply the appropriate conversion factor to convert between other Metric weight units.

Mass or Weight?

The confusion between mass and weight often arises due to their close association and the way they are used interchangeably in everyday language. This confusion often occurs because weight is commonly referred to as "mass" in everyday language.


Mass is a fundamental property of matter and represents the amount of substance in an object. The mass of an object remains the same regardless of its location in the universe. In the International System of Units (SI), the standard unit of mass is the kilogram (kg), in the Imperial system, standard unit of mass is the pound (lb).


Weight is the force with which gravity pulls an object towards the center of the Earth. It depends on both the mass of the object and the gravitational acceleration at that location.

The standard unit of weight in the SI system is the Newton (N), while in the Imperial system, it is commonly referred to as pound-force (lbf).