Use the calculators on this page to convert common units of measurement. Read this short tutorial to learn more about converting units of measurement.
Rounding errors may occur because of the floating-point calculations.
Why doesn't this work?
Which pound should I use?
There are three types of pounds listed in the mass conversion
What is the relationship between pound-mass and pound-force?
In standard Earth gravity, a 1 pound-mass has a weight of 1 pound-force.
How do I convert quarts/cups/bushels into pounds/grams/tons?
That is not a measurement conversion. You must know the density of something to calculate its mass. Density is defined as mass per unit volume:
d = m/Vsolving for m,
m = Vd.
In other words, the mass of something is its density times its volume.
Example: Given that the density of mercury is 13.456 g/cm3, find the mass of 4.7 quarts of mercury:
For common substances, you may be able to find a table of densities. Some things, like vegetables, probably won't be listed anywhere.
What are International Units (IU)?
International Units are used to measure certain vitamins, and the conversion to milligrams varies by vitamin. See this page for more information.
How much are 10,000 Japanese Yen worth in US dollars?
Currency conversion rates fluctuate constantly and are beyond the scope of this page. Try www.onada.com/converter/classic.
What are Luminance and Illuminance?
These are units for measuring light. Rather than trying to explain it here, I refer you to the Light Measurement Handbook. Also, have a look at the Lighting Design Glossary. There is also some good information on the Electro-Optical site.
Why are there decimal and binary kilobytes?In general, hard drive manufacturers use the decimal version, where 1 megabyte = 106 bytes, and everyone else uses the binary version, where 1 megabyte = 220 bytes. See this PCGuide article for a thorough explanation.
What are kibibytes, mebibytes, etc.?
These are the new prefixes for binary multiples, as proposed by IEEE. Read more about it at NIST.
I can't find my favorite unit! Would you include it?
Maybe. I welcome your suggestions.
How Many? A Dictionary of Units of Measurement: A very interesting site, giving definitions and history of many weights and measures.
General Tables of Units of Measurement (NIST): Provides some conversion tables.
A Dictionary of Units: Explains various types of measurement and provides some conversion tables.
Newtons, Slugs and Kilograms Force: Explains the relationship between dimensions for mass and weight.