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Weights & measures


NIST works to improve the accuracy of measurements, enhance consumer protection, foster fair competition, and facilitate economic growth and trade through technical activities that promote uniformity in national and international legal metrology laws, regulations, standards, test procedures and enforcement.

Get What You Pay For: At the Grocery Store

News and Updates


5710 Basic Uncertainty Concepts

Thu, May 20 2021, 2:00 - 4:00pm EDT
This 2-hour webinar provides a very basic introduction to uncertainty calculations and reporting using the 8-step

5711 Volume Metrology Seminar - CANCELED

Mon, Jun 7 2021, 8:00am - Fri, Jun 11 2021, 5:30pm EDT
The NIST Gaithersburg campus is currently in Phase 1 of reopening and is closed to visitors. Do not make any travel

Industry Impacts

Fare Standards for Rideshare Services

To calculate fares, app-based ride services such as Lyft and Uber don’t use traditional taxi meters, but instead combine data from GPS and cellular networks to

Projects and Programs

International System of Units (SI)

The International System of Units (SI) provides definitions of units of measurement that are widely accepted in science and technology and which set measurement


Redefining the kilogram and other SI units

Stephan Schlamminger
Units are at the heart of science and technology. Most measurements require units to express their result. The International System of Units (SI) provides a