Why is the pound, ton, etc. not listed under units of force?
What we call a pound (or whatever) of force is its weight when it is at rest on Earth s surface. We do that, because Earth s surface gravity is fairly (not completely) uniform. Earth s surface gravity as offered by The Universal Units Calculator is a conventionally accepted average. Obsolete engineering units of force are based on the weights of unit masses. They are available in The Universal Units Calculator by juxtaposition of the unit masses with Earth s surface gravity. Back to Table of Contents Why does the units list not include kilograms, square inches, pounds per square inch, … ? Part of the reason The Universal Units Calculator can aspire to be Universal without being unwieldy, is that it can form many units as compounds of a wieldy set of units and prefixes. The kilogram is not explicitly listed, because it can be formed from the gram, which is listed, and the prefix kilo . The square inch is similarly available from the inch and the prefix square. You can combine a quanti
