The US Metric Association (USMA), Inc., is a national non-profit organization that was founded in 1916. USMA advocates completing the US conversion to the International System of Units, known by the abbreviation SI (“ess-eye”) and also called the metric system. The process of changing measurement units to the metric system is called metric transition or metrication.
What’s new
- PDF of the May/June 2021 issue of Metric Today is now available online for USMA members.
- PDF of the March/April 2021 issue of Metric Today is now available online for USMA members.
- PDF of the January/February 2021 issue of Metric Today is now available online for USMA members.
- PDF of the November/December 2020 issue of Metric Today is now available online for USMA members.
- New “Metric Week activities for teachers/educators” section is now available below (with new items 3 through 5).
- PDF of the September/October 2020 issue of Metric Today is now available online for USMA members.
- Now available: USMA’s new 250 mm (25 cm) plastic ruler (see immediately below).
Now available: USMA’s new 250 mm (25 cm) plastic ruler
Replaces our 200 mm (20 cm) ruler which sold out. Marked in millimetres on one side, and in centimetres on the other side. Includes the USMA logo and USMA web URL, as well as the New SI logo. Also, length equivalences on one side; and area, volume, and mass equivalences on the other side.
- $1.00 each in small quantities, shipping/handling included
- 90 cents each for 10 or more, shipping/handling included
- 80 cents each for 100 or more, shipping/handling included
See USMA’s supplies list for this and other metric supplies and training aids.
Is your company or organization going metric?
We’d like to know.
Perhaps your hospital is changing over to measuring patients’ height and weight in metric units only, or your company’s product line is going hard metric. We’d be very interested in the how and the why. And, with your permission, we’ll tell your story in our newsletter, Metric Today. Please contact USMA.
Information about USMA
USMA and its services
- USMA mission and activities (Why we exist, and what we do)
- A brief history of the USMA (1916 to the 2010s)
- USMA’s Certified Metrication Specialist (CMS) program (How to become qualified)
- USMA’s Science Fair awards program (Become a judge, use your metric talents)
- USMA’s E-mail Listserver (Mailing List) (Join the metric discussion. You can subscribe free.)
- USMA member-only information (Must be a current dues-paying member to access this information. USMA members may receive the password (changed yearly) by contacting USMA.)
- USMA/Blake Family Foundation Metric Awards (A scholarship award and a non-student award.)
Publications and supplies
- Metric Today, the USMA newsletter (USMA’s bi-monthly publication)
- Metric supplies and training aids (Available from USMA: style/usage guides, rulers, thermometers, measuring tapes, posters, diagrams, bumper stickers, and booklets)
- Guide to the Use of the Metric System (Our primary metric publication)
- Metric Bibliography and Metric Today Archive (Metric information available for research purposes)
- Metrication resources for businesses (Help for business/government members converting to metric)
- Metric posters (Here’s what’s available from USMA)
- USMA’s educational materials (See below, or click on this link)
Membership
- USMA membership application (How to join us, how to help the cause)
- Officers (USMA’s organizational leaders)
Metric system information
Why use the metric system?
- FAQ: Frequently asked questions (Answers to miscellaneous questions about the metric system)
- Decimal nature of the metric system (Why decimal is better)
- How going metric pays off (Stories of successful transition to metric)
- Unit mixups (Incidents, and in some cases costly disasters, that involved confusion between units or systems of measurement)
Using the metric system
- Commonly used metric system units, symbols, and prefixes (The basics of the metric system)
- Detailed list of units, symbols, and prefixes, plus SI unit diagrams (Charts showing relationships)
- SI prefixes and their etymologies (Origins of the prefix names)
- SI unit definitions (Official definitions, both current and previous)
- Correct SI/metric usage (Including metric errors seen frequently)
- Metric temperature scales (Celsius and Kelvin)
- Glossary of metric acronyms (initialisms, and abbreviations)
Background & history
- Origin of the metric system (From its origins to becoming adopted by most of the world)
- A chronology of the metric system (Important dates and associated documents in the history of the metric system)
- Metric-system-related events and anniversaries (Some are observed each year)
- Metric system laws and bills (Extensive law summaries.)
- Metrication in other countries (Advance of metric usage in the world, and how several other countries have changed to metric)
- Recent international metric advances (What is changing metrically outside of the US)
- Logos used in various metric transitions (Take the quiz and learn about metric progress around the world.)
- Decimal currency systems (Used throughout the world)
For your information
- Reference publications: International System of Units (SI) (Important metric documents and standards: SI/metric usage guides, a few are free, some contain large tables of unit conversion factors.)
- Published articles about the metric system, metrication, and related standards
- Consumer products available in metric sizes (Examples of rational metric sizes/metric fills)
- Metric signs in the US (Some were installed in the 1970s, others are much newer)
- Our world in (metric) numbers
- Metric system cartoons (Examples of metric humor)
Things you can do
- Things you can do to promote metrication in the US
- How to contact your legislators (Senate, House of Representatives, and White House)
Metric system information for teachers/educators
- Why teach the metric system (SI)?
- Using the metric system (SI) (A guide for teachers, students, and professionals.)
- Suggestion to teachers for a painless way to teach one facet of SI (Metric Patrol assignment sheets and work sheets are included to make it easier for teachers to implement this assignment.)
- Teaching metric to very young children (K–2)
- One school’s experience in teaching math and science through Olympic Games competition
- Decimal nature of the metric system (Why decimal is better)
- Metric flashcards (PDF version): Basic and Advanced (Courtesy of USMA member Jim Elwell)
Metric Week activities for teachers/educators
- National Metric Week (The history of, and quizzes and puzzles for use during this annual event and throughout the year.)
- Tips to educators for teaching the metric system, and ideas for schools celebrating National Metric Week (Ideas and lesson suggestions)
- Daily Metric Week activities (Join the celebration!)
- Metric Week social media toolkit (Ideas and lesson suggestions)
- Metric Week governor proclamations (A challenge for every state and territory)
Need metric supplies?
USMA offers a selection of books, charts, posters, rulers, measuring tapes, bumper stickers, and thermometers specifically for learning the metric system.
These and more items can be found on USMA’s
metric supplies and training aids page.
Your comments, suggestions, and questions are welcome.
Contact USMA
Links to other selected (non-USMA) metric system information, standards, guides, and policies
Last updated: 2021-04-30