NIST Metric Information and Conversions
- Factsheets, regulations and conversion tools. Official site of the United States Metric Program.
- http://ts.nist.gov/WeightsAndMeasures/Metric/mpo_home.cfm

On-Line Measures Converter
- Length, area, mass and weight, volume and capacity, temperature, angles, force, torque, electricals, cloth sizes, and some others.
- http://amedvedev.chat.ru/

The Modern Metric System
- Dictionary of metric units explaining the principles and history of the system.
- http://metre.info/

The Scale of Things
- Illustrated examples of sizes in the metric system, from ters- to pico-.
- http://www.cefic.org/metricscale/scale.htm

Measuring Low Concentrations
- Explains with many examples the question of "What do ppm, ppb, ppt and ppq stand for?"
- http://www.cefic.org/metricscale/low_concentration.htm

National Weights and Measures Laboratory (UK)
- Official imperial-to-metric conversion tables.
- http://www.nwml.gov.uk/faqs.aspx?ID=8

Unit Conversion and Day of the Week
- Converts such things as inches to centimetres, gallon to cubic metres or even curie to becquerel
- http://scphillips.com/units//index.html

iAgora Conversions
- Converts temperature, currency, length, and mass.
- http://www.iagora.com/itravel/tools/

Conversions-R-Us
- Convert units of measurements, bases, and PPT, RTF, DOC, and XLS files to HTML.
- http://freegroups.net/conversion/

Conversion Tables
- More than 40 different unit conversion tables.
- http://www.conversiontables.info

WWW Unit Converter
- Converts area, density, energy, force, length, mass, power, pressure, speed, temperature and volume, bits and bytes.
- http://www.digitaldutch.com/unitconverter/

World Wide Metric
- Java metric conversion calculator for length, weight, pressure, and volume.
- http://www.worldwidemetric.com/metcal.htm

Unit Converters
- Features conversion calculators for atmospheric pressure, volume, distance, weight, velocity, temperature, and force.
- http://www.scorpiosite69.freeserve.co.uk/conversions.htm

Unit conversion and Reference Tables
- Features converters for physical constants, SI units, temperature, currency, and temperature.
- http://www.chemie.fu-berlin.de/chemistry/general/index_en.html

Metric Conversions
- Online calculator converts between metric, British, and American units.
- http://www.sciencemadesimple.com/conversions.html

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.
- http://www.ronshardwebapps.com/conversions.asp

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.
- http://www.projects.ex.ac.uk/trol/scol/

Online Converters
- Provide online javascript converters and calculators for converting metric to imperial units and vice-versa.
- http://onlineconverters.com

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.
- http://www.onlineconversion.com/

MIT 3.091 Units Converter
- A tool for engineers and others to convert from almost any set of units to any other.
- http://web.mit.edu/course/3/3.091_dev/javaexamples/Hello/unit-convert.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.
- http://www.convertit.com

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).
- http://n93.cs.fiu.edu/measures/

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.
- http://physics.nist.gov/cuu/Constants/energy.html

Metric System Formulas
- Formulas for converting imperial system into metric system. Site in both English and French.
- http://www.rocler.qc.ca/dusablon/wintips/

MegaConverter
- Resource for units, weights, measures, calculators and converters.
- http://www.megaconverter.com/

Measurement Unit Converter
- Converts many units of measurement using a JavaScript 1.1 applet.
- http://www.people.virginia.edu/~rmf8a/convert.html

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.
- http://hemsidor.torget.se/users/b/bohjohan/convert/conv_e.htm

Math Connect
- Provides calculations of various types including metric conversion, engineering calculations, and computing finance loan payments. Also, has list of general math formulas.
- http://www.mathconnect.com

Interactive Unit Equivalency Table Generator
- Generates an equivalency table from any engineering unit to any other.
- http://www.triatek.com/TriaUtil/unitconvtable.htm

GoConvert
- Convert currencies and measurements.
- http://www.goconvert.com/

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.
- http://www.footrule.com/

Equatorial to Galactic Converter
- Convert Equatorial to Galactic Coordinates.
- http://fuse.pha.jhu.edu/support/tools/eqtogal.html

EngNet Engineering Units Converter
- Online calculator provides conversions between a number of common (and not so common) units.
- http://www.engnetglobal.com/tips/convert.asp

eFunda: Units and Constants
- The index page for units, fundamental constants, and currencies.
- http://www.efunda.com/units/index.cfm

Measurement Units Translation
- Measurements converter for time, length, volume, and weight. Requires JavaScript.
- http://www.convert-me.com/en/

Convert-Me
- Metric, English old Russian, ancient Greek and Roman, nautical, typographical and astronomical conversions.
- http://www.convert-me.com

GourmetSleuth
- Conversion calculators for distance, length, area, volume weights, and temperature.
- http://www.gourmetsleuth.com/general_calcs.htm

Chinese Numbers
- Put in a number and get the Chinese representation of that number. Also, converts from Arabic numeral back to the Chinese form.
- http://www.mandarintools.com/numbers.html

Body Height Weight Converter
- Converts from American to metric units and vice versa.
- http://www.albireo.ch/bodyconverter/

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.
- http://allchin.net/converter/

Metric Conversion Tables to Imperial Measurements
- Standard-to-metric conversion factor tables with definitions, derived units and prefixes.
- http://www.simetric.co.uk/

British Weights and Measures Association (BWMA)
- Pressure group opposing compulsory metrication. Political, consumer and transport information, discussion boards and links.
- http://www.bwmaonline.com/

The Metric System
- Outline of the metric system with emphasis on applications in physics.
- http://www.essex1.com/people/speer/metric.html

Anglo-Saxon Weights & Measures
- Catalogue of traditional British units with historical notes.
- http://members.aol.com/Jack%20Proot/met/spvolas.html