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Office of Weights and Measures

Our Mission: To promote uniformity in national and international legal metrology laws, regulations, standards, test procedures, and enforcement practices to ensure measurement traceability to the International System of Units (SI) and to facilitate consumer protection, marketplace equity, and economic growth and trade.

As the National Metrology Institute for the U.S., NIST through the Office of Weights and Measures (OWM) provides documentary standards and services for legal metrology -- the practice and process of applying regulatory structure and laws enforcement to metrology.  OWM's mission is to ensure national uniformity in legal metrology and to deliver standards and services to achieve equity in the commercial marketplace.  This is directly aligned with the NIST mission to promote U.S. industrial competitiveness and enhance economic security.  Originally established in 1836 as the “Office of Construction of Standard Weights and Measures”, OWM also remains the oldest office at NIST.  For more information, see A Brief History of OWM.

Nearly 50 percent of the U.S. Gross Domestic Product is impacted by the sales of products and services based on weights or measures.  Industry sectors potentially affected by legal metrology standards include retail food sales, petroleum products, transportation, and chemicals, including emerging commercial market sectors such as charging of electric vehicles and e-commerce.  OWM programs aim to ensure consumers get what they pay for, and sellers get fair payment for the goods and services they sell based on weight or measure through a uniform measurement infrastructure.  This, in turn, promotes consumer confidence and helps ensure fair competition spanning local business operations to commerce on a global scale.

In practice, OWM works with State and local weights and measures agencies, Federal agencies, industry and consumer groups, and national and international standards development organizations (SDOs) to design, develop, promote and deliver the following standards and services 

  • technical specifications and tolerances for weighing and measuring devices;  
  • uniform laws, regulations, methods of sale, and test procedures for a wide variety of commodities;  
  • training for laboratory metrologists and weights and measures officials;  
  • uniformity and harmonization of national and international legal metrology principles;  
  • usage of the International System of Units (the SI or modern metric system).

See Programs for detailed information regarding OWM’s programmatic activities and staff expertise.  


News and Updates


5816 Fundamentals of Metrology

Mon, Oct 17 - Fri, Oct 21 2022
The 5-day Fundamentals of Metrology seminar is an intensive course that introduces participants to the concepts of



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