9 units · 72 conversions

Weight & Mass Converter

Convert between grams, kilograms, pounds, ounces and more.

Popular Weight & Mass conversions

Grams to Kilograms g → kg Grams to Milligrams g → mg Grams to Micrograms g → µg Grams to Metric Tons g → t Grams to Pounds g → lb Grams to Ounces g → oz Grams to Stones g → st Grams to Carats g → ct Kilograms to Grams kg → g Kilograms to Milligrams kg → mg Kilograms to Micrograms kg → µg Kilograms to Metric Tons kg → t Kilograms to Pounds kg → lb Kilograms to Ounces kg → oz Kilograms to Stones kg → st Kilograms to Carats kg → ct Milligrams to Grams mg → g Milligrams to Kilograms mg → kg Milligrams to Micrograms mg → µg Milligrams to Metric Tons mg → t Milligrams to Pounds mg → lb Milligrams to Ounces mg → oz Milligrams to Stones mg → st Milligrams to Carats mg → ct Micrograms to Grams µg → g Micrograms to Kilograms µg → kg Micrograms to Milligrams µg → mg Micrograms to Metric Tons µg → t Micrograms to Pounds µg → lb Micrograms to Ounces µg → oz

All Weight & Mass conversions (72)

All Weight & Mass units

Grams g Kilograms kg Milligrams mg Micrograms µg Metric Tons t Pounds lb Ounces oz Stones st Carats ct

About Weight & Mass

This category covers the nine units used to measure weight and mass in shops, kitchens, gyms, laboratories and freight: grams, kilograms, milligrams, micrograms and metric tons from the metric system, pounds, ounces and stones from imperial and US customary use, and carats, the specialist unit for gemstones. The reasons people arrive here are wonderfully varied: following a recipe written on the other side of the Atlantic, reading a body weight that a US site quotes in pounds and a UK doctor quotes in stones, checking a shipping limit, converting a supplement dose printed in micrograms, or pricing a stone by carat. The pairs that get used most are kilograms to pounds, grams to ounces, pounds to kilograms and stones to kilograms.

There is one genuine distinction worth knowing here, and it catches people out. Mass is how much matter something contains and does not change wherever you take it. Weight, strictly speaking, is the force gravity exerts on that mass, which is why an object would weigh less on the Moon while its mass stayed identical. In ordinary use, on Earth, the two are treated as interchangeable, and that is the sense every page in this category uses: you put in a quantity of stuff and get the same quantity expressed in another unit. If you actually need force rather than everyday weight, the force converter is the right hub. The other thing to know is where each unit lives. Kilograms and grams are the world default. Pounds and ounces run through American cooking and US body weight. The stone is essentially British and is used almost exclusively for people, which is why a UK weight is often quoted as stones plus a remainder in pounds rather than as a decimal.

Each pair page shows you the formula it used, walks through a worked example, and lists a table of common conversions you can scan without typing anything, which is handy when you are mid-recipe with floury hands. Everything is free, nothing needs an account, and the whole calculation happens inside your browser, so no value you enter leaves your device. The conversions are straightforward ratios, which means you can go in either direction and get back exactly where you started.

Frequently asked questions

Is there a real difference between weight and mass?

Yes, in physics. Mass is the amount of matter in an object and never changes. Weight is the force gravity applies to that mass, so it depends on where you are. In everyday life on Earth the two are used interchangeably, and that is how these converters work: grams, kilograms, pounds and the rest are all treated as measures of the same quantity. If you specifically need force, in newtons or pound-force, use the force converter instead.

What is a stone and who uses it?

The stone is an imperial unit used almost entirely in the United Kingdom and Ireland, and almost entirely for body weight. A British person is far more likely to give their weight in stones than in pounds or kilograms. It rarely appears anywhere else, which is why visitors from the US or Europe often need to convert it. The stones pair pages handle it in both directions.

Why does a recipe give ounces when I only have a metric scale?

Most American recipes measure by ounces and pounds, while most kitchen scales sold outside the US default to grams and kilograms. Converting the ingredient weights is the reliable fix, and the grams to ounces page and its reverse cover it. Be aware that an ounce of weight is not the same thing as a fluid ounce of volume, so if the recipe means a liquid measure you want the volume converter instead.

What is a carat used for?

The carat is the standard unit for the mass of gemstones and pearls, and it is why diamond prices are quoted per carat. It is a small unit, closer in scale to a fraction of a gram than to anything you would weigh in a kitchen. Do not confuse it with the karat that describes gold purity, which is not a weight at all but a measure of how much of an alloy is gold.

Other converters

Length Temperature Volume Area Speed Digital Storage Time Pressure Energy Angle Power Frequency Force