Weight Converter
Convert between weight units — kilograms, grams, milligrams, metric tons, pounds and more.
Reviewed by the ToolNestr Editorial Team — July 2026
About this weight converter
Weight (mass) is measured in metric and imperial units that this tool moves between. This weight converter lets you move between 7 different weight units in either direction. Pick the unit you are starting from, the unit you want, and enter a value — the result appears instantly as you type, with the calculation running entirely in your browser.
Internally, every unit is defined by its exact ratio to a single base unit, the kilogram. To convert, the tool first changes your value into the base unit, then into the target unit. This base-unit method keeps results consistent and precise no matter which pair of units you choose, and makes it easy to add uncommon units alongside the everyday ones.
Use the swap control to reverse the direction at any time, which is handy when you are checking a figure both ways. Because the converter is mobile-first and works offline once loaded, it is a quick reference for weight whether you are studying, working, travelling or shopping across measurement systems.
Supported weight units
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Frequently asked questions
How does this weight converter work?
Choose the unit you have and the unit you want, type a value, and the tool converts it via a common base unit (the kilogram). It supports 7 weight units.
Is the weight converter accurate?
Yes. Every unit is defined by its exact ratio to the kilogram, so conversions are precise; displayed results are rounded for readability.
Can I convert in both directions?
Yes. Swap the “from” and “to” units, or press the swap button, to convert either way between any two weight units.
Which weight units are supported?
It includes Kilograms, Grams, Milligrams, Metric tons, Pounds, Ounces, Stone.