Weight & Mass Converter

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   What’s great about our Weight & Mass Converter

   Fast, accurate conversion of weights and masses that you can see and drag

   • Free
   • Converts milligrams, grams, kilograms, tonnes, ounces, pounds and stones instantly
   • Synced sliders and type-in boxes
   • No sign-up
   • No ads
   • Works offline once loaded
   • No daily limit
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   Choose which units to show

   Use the unit names at the top to show or hide each card. Drag a name or a card’s title to rearrange them; your order is remembered in this browser, and Restore puts the original order back.

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   Drag a slider or type a value

   Move any slider, or type a number into its “Type Value” box, and every visible unit updates instantly. The sliders are logarithmic, so each step along a slider multiplies the value, and one slider covers very small to very large amounts.

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   Widen the range

   Turn on “Wider Range” to widen every slider’s range to cover more extreme values.

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What is Weight and Mass?

Mass is how much matter an object contains, and weight is the force of gravity pulling on that mass. In everyday life people use the two words for the same thing, and scales show it in kilograms or pounds. This converter changes between metric units such as grams and kilograms and imperial units such as ounces, pounds and stones.

About Milligrams (mg)

A milligram is one thousandth of a gram. It is used for doses of medicines and vitamins and for tiny amounts in science and food labeling.

• 1 mg = 0.001 g, and 1,000,000 mg = 1 kg
• 1 mg is about 0.0000353 oz
• Many vitamin and medicine doses are written in milligrams

About Grams (g)

The gram is a metric unit of mass equal to one thousandth of a kilogram. It is the everyday unit for food, ingredients and small items.

• 1 g = 1,000 mg, and 1,000 g = 1 kg
• A paperclip weighs about 1 gram
• 1 oz is about 28.35 g

About Kilograms (kg)

The kilogram is the base unit of mass in the SI system. Since 2019 it has been defined using the Planck constant instead of a physical object.

• 1 kg = 1,000 g, or about 2.2046 lb
• Body weight, groceries and luggage are measured in kilograms in most countries
• Airlines often allow checked bags of about 23 kg

About Tonnes (t)

A tonne, or metric ton, is 1,000 kilograms. It is used for heavy loads such as cargo, vehicles, crops and industrial output.

• 1 t = 1,000 kg, or about 2,204.6 lb
• The US short ton (2,000 lb) and the UK long ton (2,240 lb) are different units
• A small car weighs roughly 1 to 1.5 tonnes

About Ounces (oz)

The ounce is an imperial and US customary unit of mass. The avoirdupois ounce used for everyday goods is exactly 28.349523125 grams.

• 16 oz = 1 lb
• A troy ounce (31.1035 g) is a different unit, used for gold and silver
• Not the same as the fluid ounce, which measures volume

About Pounds (lb)

The pound is an imperial and US customary unit of mass, defined since 1959 as exactly 0.45359237 kilograms.

• 1 lb = 16 oz, and 14 lb = 1 stone
• Body weight is commonly given in pounds in the US
• The abbreviation lb comes from the Roman libra

About Stones (st)

The stone is a British unit of mass equal to 14 pounds, or about 6.35 kilograms. It is still commonly used in the UK and Ireland for body weight.

• 1 st = 14 lb, or about 6.35 kg
• Weights are given like “11 st 4 lb”
• The US does not use stones for body weight