Units of Measurement Websites

A dictionary of units of measurement: explanations of the metric system, System Internationale (SI), English customary system, and other modern measuring systems. Plus extensive links to other measurement-related Internet resources.

A site promoting the metric system which argues why metric is better and English is worse. Provides an English-metric online calculator.

Pressure group campaigning for the completion of metrication in the UK. History, legislation, and practical help.

History and usage of English/Imperial/customary weights and measures, with conversion factors, and pictures. Minims, drachms, pecks, bushels, rods, poles, perches, furlongs, ounces, fathoms, pints, gallons, nails, chains, chaldrons, tods, crowns, florins, groats, farthings and guineas.

Definitions of SI units and SI prefixes, units outside the SI, rules and style conventions, historical context for SI units, international aspects of the SI, and unit conversions.

Conversions tables and equivalences of the principal units of measure of the SI and Anglo-Saxon systems.

Pressure group opposing compulsory metrication. Political, consumer and transport information, discussion boards and links.

Standard-to-metric conversion factor tables with definitions, derived units and prefixes.

Convert units from one measure to another (e.g. meters to yards, liters to gallons). A very extensive collection of units and categories. Includes usage and definitions descriptions of units and categories.

Physics laboratory of the National Institute of Standards and Technology (NIST) sponsors and maintains this reference resource of CODATA-recommended values of fundamental physical restraints.

Offers a wide variety of unit conversion tools and conversion charts for fast lookup.

Book by Wacek Kijewski on experimental science in metric units. Includes problems, guided solutions, fun facts, data handling and metric conversion tests.

Includes information about the National Measurement System, legislation and guidance, services to industry, and its enforcement role.