The definition, agreement and practical use of units of measurement have played a crucial role in human endeavour from early ages up to this day. Disparate systems of measurement used to be very common. Now there is a global standard, the International System (SI) of units, a form of metric system. The SI has been or is in the process of being adopted throughout the world. The United States of America is almost certainly the last to adopt the system but even there it is increasingly being used.
Standards are very important. Each unit is a set size. A distance or length or volume or mass or span of time being measured is described as a certain number of these units. A measurement may be quoted to a certain degree of accuracy.
One example of the importance of agreed units is the failure of the NASA Mars Climate Orbiter, which was accidentally destroyed on a mission to the planet Mars in September 1999 instead of entering orbit, due to miscommunications about the value of forces: different computer programs used different units of measurement (newton versus pound force). Enormous amounts of effort, time and money were wasted.
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Measures - Catalogue of traditional British units with historical notes.
Meta Description: [ physical units - weights and measures - equivalencies for the Anglo-Saxon system - its history ]
All Measures - Conversion table of non-metric measures into SI and CGS.
Meta Description: [ Allmeasures.com presents conversion table of non-metric measures into SI(meter-kilogram-second +) and CGS (centimeter-gram-second), two-way javascript converter, temperature conversion table and converter, bibliography (selected books about units of measure) ]
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.
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Body Height Weight Converter - Converts from American to metric units and vice versa.
Meta Description: [ Converts Feet, Inches and Lbs to Centimeters and Kilograms and vice versa ]
British Weights and Measures Association (BWMA) - Pressure group opposing compulsory metrication. Political, consumer and transport information, discussion boards and links.
Meta Description: [ BWMA exists to protect and promote customary UK/imperial weights and measures, and to oppose compulsory conversion to the metric system. ]
Chinese Numbers - Put in a number and get the Chinese representation of that number. Also, converts from Arabic numeral back to the Chinese form.
Meta Description: [ All About Chinese Numbers. Find Chinese equivalents to English numbers. ]
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.
Meta Description: [ Information and assistance on most aspects of teaching, learning, and using mathematics ]
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).
Meta Description: [ Allmeasures.com presents conversion table of non-metric measures into SI(meter-kilogram-second +) and CGS (centimeter-gram-second), two-way javascript converter, temperature conversion table and converter, bibliography (selected books about units of measure) ]
Conversion Tables - More than 40 different unit conversion tables.
Meta Description: [ Interactive unit conversion calculator with more than 50 different 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.
Meta Description: [ Conversion and Calculation Center home page that contains links
to our measurement conversion, currency exchange rate, world time zone, reference information,
and other pages. ]
Convert-Me - Metric, English old Russian, ancient Greek and Roman, nautical, typographical and astronomical conversions.
Convert-me.Com - Interactive calculators for many common and exotic measurement systems, including metric, Ancient Greek, Roman, and old Russian.
eFunda: Units and Constants - The index page for units, fundamental constants, and currencies.
Meta Description: [ 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.
Meta Description: [ English weights & measures: History, Current usage etc. ]
EngNet Engineering Units Converter - Online calculator provides conversions between a number of common (and not so common) units.
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Equatorial to Galactic Converter - Convert Equatorial to Galactic Coordinates.
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Fuzzycrawler - Converts metric, imperial, energy, torque, acceleration, mass, force, length, light, mass force, and electricity.
GoConvert - Convert currencies and measurements.
Meta Description: [ We invite you to use our interactive tools to convert an incredible amount of units of measurement from all corners of the globe. You can quickly and easily convert the most popular units of currency, weight, speed, length, volume, area and many others - for Free! It's all here - you can convert... ]
GourmetSleuth - Conversion calculators for distance, length, area, volume weights, and temperature.
Meta Description: [ 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.
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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.
Meta Description: [ Calculation, metric conversion and more. ]
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.
Meta Description: [ Convert volume (capacity), weight, length, area, temperature and pressure measures between U.S./Imperial and SI (Metric) units ]
Measurement Unit Converter - Converts many units of measurement using a JavaScript 1.1 applet.
Meta Description: [ Measurement unit converter for temperature,
length, area, volume, etc using JavaScript1.1 for older browser support. ]
Measurement Units Translation - Measurements converter for time, length, volume, and weight. Requires JavaScript.
MegaConverter - Resource for units, weights, measures, calculators and converters.
Meta Description: [ Best Place to Figure What Equals What. megaConverter is THE 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.
Meta Description: [ Let's face it: Metric is the better system! ]
Metric Conversion Tables - Conversion factors and online calculators for metric and imperial units.
Meta Description: [ Get metric conversion tables and charts for converting measurement units into or out of the metric system. ]
Metric Conversion Tables to Imperial Measurements - Standard-to-metric conversion factor tables with definitions, derived units and prefixes.
Meta Description: [ Over 1000 Standard to Metric Conversion Factor Tables with Definitions, Derived Units and Prefixes ]
Metric System Formulas - Formulas for converting imperial system into metric system. Site in both English and French.
Meta Description: [ metric conversion formulas for grams in weight liters in capacity centimeters in measurement kilometers in distance degree celcius in weather. ]
MIT 3.091 Units Converter - A tool for engineers and others to convert from almost any set of units to any other.
Ninja Suit - Features online converters for business, consumers, education, science, travel, research and enjoyment purposes.
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NIST Metric Information and Conversions - Factsheets, regulations and conversion tools. Official site of the United States Metric Program.
Meta Description: [ Page not found. ]
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.
Meta Description: [ Online Conversion is a resource for weights, measures, calculators, converters. ]
Online Converters - Provide online javascript converters and calculators for converting metric to imperial units and vice-versa.
Meta Description: [ FREE Online Measurements Converters and Calculators ]
Online Unit Converter - Personalizable, free, and available in five languages. It converts distance and length, area, capacity and volume, pressure, temperature, and speed.
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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.
Meta Description: [ metric Unit Conversion Calculators for any browser. ]
Science Made Simple - Online metric converter gives U.S. customary and metric conversions.
Meta Description: [ Metric conversions and US customary units - use the online metric converter and tables for unit measurements including temperature, weight, volume, area, length, plus currency converter, fractions & more by Science Made Simple. ]
SI Guide - Provides translation of unit and prefix names for the international metric system (SI) into various languages. For some, transliterations are also given.
Meta Description: [ A compact set of information about the international metric system (SI), including foreign language guides. ]
SI Units - Reference information on the International System of Units (SI).
Temperature Converter - Converts Fahrenheit to Celsius and vice versa.
Meta Description: [ A temperature converter for Celsius and Fahrenheit ]
Temperature Converter - Simple Celsius-Fahrenheit conversions.
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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.
Meta Description: [ Tables of unusual measures such as Wool Weights, Yarn Lengths, Coal Weights,
Butter Weight, Hay and Straw capacities, Timber Capacity, Cotton Wool Weights & Miscellaneous Liquid Measures. ]
The Metric System - Outline of the metric system with emphasis on applications in physics.
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The Modern Metric System - Dictionary of metric units explaining the principles and history of the system.
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
Meta Description: [ A list of unit conversion factors and a
units calculator. Also a calculator to tell you what day of the week a date
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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.
Meta Description: [ Chemie.DE Unit Converter / Chemie.DE Einheiten-Umrechnung ]
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Unit Conversions - Features physics converters for angular speed, area, electrical current, energy, force, magnetic flux, pressure, resistance, speed, time, voltage, and volume.
Unit Converters - Features conversion calculators for atmospheric pressure, volume, distance, weight, velocity, temperature, and force.
Meta Description: [ java unit conversions - converts anything ]
Units of Measurement - Conversions and equivalences of the principal units of measure of the SI and Anglo-Saxon systems.
Meta Description: [ Conversions of the units of measure of the SI and equivalent Anglo-Saxon. International System of units, surface, lengths, weights, capacity, diameters, temperature, BEAUFORT, volumes, pressures, bores, AWG, empty, angles, speed, thread, clothes, calendar, numerations, etc. ]
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.
Meta Description: [ The WWW Unit Converter - Online conversion of area, density, energy, force, length, mass, power, pressure, speed, temperature, volume and bytes. ]
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