Weight & Mass Converter

Weight conversion is the single most-searched conversion there is, and almost all of it comes down to one number: a pound is exactly 0.45359237 kg. Every other imperial mass unit is defined from it — an ounce is a sixteenth of a pound, a stone is fourteen pounds.

Two cautions worth knowing. First, the ounce here is the avoirdupois ounce used for groceries and body weight, not the troy ounce used for precious metals (which is heavier, at about 31.103 g). Second, a fluid ounce measures volume, not weight — if you are converting a liquid recipe, you want the volume converter instead.

Common weight & mass conversions

Every weight & mass unit CalcBoard converts

All 7 units in this category, with the exact factor each one uses to reach the base unit (kilogram). These are the same constants the app computes with.

Convert without a browser

This page needs a connection. The CalcBoard app does the same conversions offline, with exact decimal arithmetic, and puts the converter next to a working calculator — so you can convert a measurement in one panel and immediately use it in a formula in the next, without copying anything by hand.

Frequently Asked Questions