How to Convert Weight and Mass Units

Convert mass while retaining enough precision for the intended use.

Use the Weight Converter alongside this illustrative example.

A practical example

A parcel of 2.5 kg is approximately 5.5116 lb using the exact pound definition. For a shipping form, follow the carrier’s rounding rule rather than rounding down because the displayed decimal looks close. Keep packaging mass in the original weighing if the limit covers the complete parcel.

Check the result

Check whether a source uses metric tonnes, US short tons or another convention. A similar-looking unit label can imply a different quantity.

Try a comparison

Weigh the packaging separately and add it to the contents before converting a shipping quantity. Compare the converted total with the carrier’s stated mass limit. If a parcel is close to the limit, use the scale’s precision rather than relying on a rounded conversion.

What this does not establish

Conversion cannot improve scale accuracy or determine a carrier’s chargeable dimensional weight. Measure and apply the provider’s current rules separately.

Report unclear guidance or a result that needs checking.