- All Measures - Conversion table of non-metric measures into SI and CGS.
- Allchin Measurements Converter - Converts common measurements from metric to imperial and vice versa, with other systems included for selected quantities such as light years, picas, and Old Russian measures.
- Anglo-Saxon Weights & Measures - Catalogue of traditional British units with historical notes.
- Body Height Weight Converter - Converts from American to metric units and vice versa.
- British Weights and Measures Association (BWMA) - Pressure group opposing compulsory metrication. Political, consumer and transport information, discussion boards and links.
- Chinese Numbers - Put in a number and get the Chinese representation of that number. Also, converts from Arabic numeral back to the Chinese form.
- Cleave Books - Specialist Calculators - Features converters for perimeter measurements of geometric figures, fractions, percentages, number bases, loan repayments, growth and decay, cost of living index, fuel consumption, flow rate, specific energy, viscocity, and heat capacity.
- Conversion Factors for Energy Equivalents - 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.
- Conversion Table of Non-Metric measures into SI and CGS - Conversion of non-metric measures into SI (meter-kilogram-second) and CGS (centimeter-gram-second).
- Conversion Tables - More than 40 different unit conversion tables.
- Conversions-R-Us - Convert units of measurements, bases, and PPT, RTF, DOC, and XLS files to HTML.
- Convert It - Features converter tools for measurement, currency exchange, world time zones, time, finance, driving distance, Roman numerals, atmosphere, and body mass index. Also, has a basic calculator and periodic table.
- Convert-Me - Metric, English old Russian, ancient Greek and Roman, nautical, typographical and astronomical conversions.
- eFunda: Units and Constants - The index page for units, fundamental constants, and currencies.
- English Weights and Measures - 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.
- EngNet Engineering Units Converter - Online calculator provides conversions between a number of common (and not so common) units.
- Equatorial to Galactic Converter - Convert Equatorial to Galactic Coordinates.
- GoConvert - Convert currencies and measurements.
- GourmetSleuth - Conversion calculators for distance, length, area, volume weights, and temperature.
- How Many? - 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.
- iAgora Conversions - Converts temperature, currency, length, and mass.
- IEER Technical Classroom - Table of conversion factors for selected units relevant to nuclear topics.
- Interactive Unit Equivalency Table Generator - Generates an equivalency table from any engineering unit to any other.
- International System of Units - 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.
- Math Connect - Provides calculations of various types including metric conversion, engineering calculations, and computing finance loan payments. Also, has list of general math formulas.
- Measurement Conversion - Convert volume (capacity), weight, length, area, temperature, pressure, torque, power and energy measures between U.S./Imperial and SI (Metric) units. Requires JavaScript.
- Measurement Unit Converter - Converts many units of measurement using a JavaScript 1.1 applet.
- Measurement Units Translation - Measurements converter for time, length, volume, and weight. Requires JavaScript.
- Measuring Low Concentrations - Explains with many examples the question of "What do ppm, ppb, ppt and ppq stand for?"
- MegaConverter - Resource for units, weights, measures, calculators and converters.
- Metric 4 US - A site promoting the metric system which argues why metric is better and English is worse. Provides an English-metric online calculator.
- Metric Conversion Tables - Conversion factors and online calculators for metric and imperial units.
- Metric Conversion Tables to Imperial Measurements - Standard-to-metric conversion factor tables with definitions, derived units and prefixes.
- Metric Conversions - Online calculator converts between metric, British, and American units.
- Metric System Formulas - Formulas for converting imperial system into metric system. Site in both English and French.
- MIT 3.091 Units Converter - A tool for engineers and others to convert from almost any set of units to any other.
- National Weights and Measures Laboratory (UK) - Official imperial-to-metric conversion tables.
- Ninja Suit - Features online converters for business, consumers, education, science, travel, research and enjoyment purposes.
- NIST Metric Information and Conversions - Factsheets, regulations and conversion tools. Official site of the United States Metric Program.
- On-Line Measures Converter - Length, area, mass and weight, volume and capacity, temperature, angles, force, torque, electricals, cloth sizes, and some others.
- Online Conversion - Offers conversion tools for length, volume, temperature, astronomical, clothing sizes, computer bytes, cooking measurements, time zones, density, energy, finance, flow rates, force frequency, and some fun pages.
- Online Converters - Provide online javascript converters and calculators for converting metric to imperial units and vice-versa.
- Online Unit Converter - Personalizable, free, and available in five languages. It converts distance and length, area, capacity and volume, pressure, temperature, and speed.
- Process Associates of America - Features tools for finding engineering conversion factors.
- Ron's Hard Conversion Tools - Online unit conversion calculators for volume, distance, weight, and temperature units. Also includes number conversion (decimal, hex, and binary) and a tool to convert characters to or from ASCII codes.
- SI Guide - Provides translation of unit and prefix names for the international metric system (SI) into various languages. For some, transliterations are also given.
- SI Units - Reference information on the International System of Units (SI).
- Temperature Converter - Converts Fahrenheit to Celsius and vice versa.
- Temperature Converter - Simple Celsius-Fahrenheit conversions.
- The Foot Rule - 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.
- The Metric System - Outline of the metric system with emphasis on applications in physics.
- The Modern Metric System - Dictionary of metric units explaining the principles and history of the system.
- The Scale of Things - Illustrated examples of sizes in the metric system, from ters- to pico-.
- UK Metric Association - Pressure group campaigning for the completion of metrication in the UK. History, legislation, and practical help.
- Unit Conversion and Day of the Week - Converts such things as inches to centimetres, gallon to cubic metres or even curie to becquerel
- Unit conversion and Reference Tables - Features converters for physical constants, SI units, temperature, currency, and temperature.
- Unit Conversions - Online conversions from physics units to other physics units. Includes a comprehensive set of units with definitions.
- Unit Converters - Features conversion calculators for atmospheric pressure, volume, distance, weight, velocity, temperature, and force.
- Units of Measurement - Conversions and equivalences of the principal units of measure of the SI and Anglo-Saxon systems.
- World Wide Metric - Java metric conversion calculator for length, weight, pressure, and volume.
- WWW Unit Converter - Converts area, density, energy, force, length, mass, power, pressure, speed, temperature and volume, bits and bytes.
