Weight Unit Converter

Convert between units of weight and mass.

Supported Units

• Tonne (t): The tonne, also known as the metric ton, is a unit of mass equal to 1,000 kilograms. It was introduced alongside the metric system during the French Revolution to provide a convenient measure for large masses. The tonne is used globally in trade, shipping, and industry for expressing the weight of bulk goods, vehicles, and heavy machinery. For everyday reference, a typical passenger car weighs about 1 to 2 tonnes, and an adult African elephant weighs roughly 5 tonnes.
• Kilogram (kg): The kilogram is the base unit of mass in the International System of Units (SI). Originally defined by a physical platinum-iridium prototype created in 1889, it was redefined in 2019 using the Planck constant for greater precision. It is used worldwide in everyday life, from grocery shopping to scientific research. When you step on a bathroom scale or check a food label, the measurement is typically in kilograms.
• Gram (g): The gram is one-thousandth of a kilogram and is widely used for measuring small quantities. You will find it on nutrition labels, in cooking recipes, and in postal weight limits. It was originally defined as the mass of one cubic centimeter of water at 4 degrees Celsius, making it one of the earliest metric units to be established. In scientific work, grams are commonly used for chemical reagents and laboratory samples.
• Milligram (mg): The milligram is one-thousandth of a gram and is essential for measuring very small masses. It is most commonly seen in pharmaceutical dosages, where active ingredients are specified in milligrams per tablet or capsule. Nutritional information on food packaging also lists vitamins and minerals in milligrams. In analytical chemistry and environmental science, milligrams are used to quantify trace substances in samples.
• Microgram (µg): The microgram is one-millionth of a gram, or one-thousandth of a milligram. Its symbol µg uses the Greek letter mu, denoting the SI prefix "micro." It is commonly used to express recommended daily intakes of vitamins such as vitamin D and vitamin B12. In clinical medicine, hormone levels and certain blood markers are reported in micrograms. Environmental regulations also use micrograms per liter or per cubic meter to set limits on pollutant concentrations in water and air.
• Pound (lb): The pound is the basic unit of mass in the imperial and US customary systems, defined as exactly 0.45359237 kilograms. Its name derives from the Latin "libra pondo" (a pound by weight), which also gives us the abbreviation "lb." In the United States, the pound is used for nearly all everyday weight measurements, from body weight to grocery items sold by the pound. In the United Kingdom, while metrication has progressed significantly, many people still express their body weight in stones and pounds.
• Ounce (oz): The ounce is a unit of mass in the imperial and US customary systems, equal to one-sixteenth of a pound, or exactly 28.349523125 grams. It is widely used in the United States for food packaging, postal rates, and portion sizes. Boxing gloves are rated in ounces (such as 8 oz or 10 oz), and restaurant menus often describe steak sizes in ounces. Note that the fluid ounce is a separate unit of volume and should not be confused with the ounce of mass.

How to Use

1. Select the unit you want to convert from in the "From" dropdown.

2. Select the unit you want to convert to in the "To" dropdown.

3. Enter a value and the result will be displayed in real time.

4. Use the swap button to reverse the conversion direction.