Mass Unit Converter

Mass Unit Converter

Convert mass and weight between metric and imperial units on Clayi Tools — free, in your browser, no account required. Handy for cooking, shipping, lab work, education, and everyday calculations.

What it does and when to use

Turns one mass value into another — for example kilograms to pounds, grams to ounces, or metric tons to US short tons. Use it when a recipe, label, freight quote, or homework uses a different unit than yours, and you want a quick answer without a spreadsheet.

How to use this tool

Enter a value, pick From unit and To unit, then click Convert mass. Results update as you type. Use Swap units to flip direction without re-entering the number, or Clear to reset.

Supported units

Milligram (mg), gram (g), kilogram (kg), metric ton (t), ounce (oz), pound (lb), stone (st), US short ton, UK long ton, and carat (ct). Every conversion runs through kilograms internally so results stay consistent across all pairs.

Common equivalent units table

After you convert, the tool shows your value expressed in every supported unit in one table — useful when you need pounds and kilograms side by side, or want to compare oz and g for packaging.

Copy-ready conversion report

The detailed report at the bottom lists input, output, base kilogram value, and all equivalents in plain text. Copy and paste into email, notes, or a lab log without reformatting.

Decimal places and precision

Set Decimal places from 0 to 12 (default 6). Use fewer decimals for quick estimates; use more for technical or scientific work. Display rounding does not change the underlying calculation.

Metric vs imperial in practice

Metric (mg, g, kg, t) is common in science, EU labels, and freight. Imperial (oz, lb, st, tons) appears on US/UK packaging, body weight, and older specs. Carat (ct) is standard for gems. This tool bridges all of them in one place.

Privacy and speed

All math runs locally in your browser — nothing is sent to a server. No sign-up, works offline once the page is loaded, and your numbers stay on your device.

Limitations

For legal trade measurement, medical dosing, certified lab work, or binding contracts, confirm official standards and rounding rules in your field. This tool is for everyday and general conversion use.