Weight & Mass Converter

Is a pound exactly 0.45359237 kg?

Yes. The avoirdupois pound has been defined as exactly 0.45359237 kg since 1959, and the converter uses that full value. An ounce is one sixteenth of a pound, 28.349523125 g, and a stone is 14 pounds, 6.35029318 kg.

What is the difference between a short ton, a long ton and a tonne?

A metric tonne is 1,000 kg. The US short ton is 2,000 lb (907.18474 kg), and the UK long ton is 2,240 lb (1,016.046909 kg). One tonne equals 1.102311311 short tons or 0.98420653 long tons. The three are listed separately, so check which one a contract or shipping document means.

Is this a weight converter or a mass converter?

It converts mass: the amount of matter, which stays the same everywhere. Weight is the force gravity puts on that mass and changes between Earth and the Moon. Scales and everyday speech use pounds and kilograms for both. For true force units such as newtons, use the force converter.

Is the ounce here the same as a fluid ounce or a troy ounce?

No. The ounce in this list is the avoirdupois ounce, 1/16 lb. A fluid ounce measures volume, and a troy ounce, used for precious metals, is 31.1034768 g. Troy ounces are not in this tool, so do not use it for gold or silver quotes.

Where is the stone still used?

The stone, 14 lb, is a common way to give body weight in the UK and Ireland. Under the converter, 12 st is 168 lb or 76.20351816 kg. The same 180 lb person is 12.85714286 st.

Does it give pounds and ounces together?

No. You get a single decimal answer, so 1.5 lb appears as 1.5 and not as 1 lb 8 oz. To split it yourself, take the whole pounds and multiply the decimal remainder by 16. For example, 0.5 lb is 8 oz.

How precise are the results?

Factors are exact definitions, and the display rounds to about ten significant digits. That is far beyond the accuracy of a kitchen or bathroom scale, so round the answer to match your measurement before using it.