National Metric Day - October 10


On 10/10, National Metric Day recognizes the metric system, its history, and its benefits.

The metric uses decimals as a method of measuring mass, distance, and volume. Though Simon Stevin, a Flemish mathematician, first suggested such a system in his 1586 publication De Thiende (The Tenth), centuries passed before the metric system became an accepted form of measurement.

The metric system uses the following base units:

  • Meter – measures length
  • Gram – measures mass
  • Liter – measures volume

These units are broken down by the power of 10 and the terms used for smaller and larger units carry across the base units. For example, a kilo is equal to the factor of 1000 and deci is equal to the factor of 0.1. A kilometer, kilogram, and kiloliter all mean translate to be 1000 of each base unit while a decimeter, decigram, and deciliter all translate to 0.1 of the base unit. This standardization makes for easy conversions. 

Another metric unit of measure is Celsius. Also known as centigrade, this unit measures temperature. The boiling and freezing points of water are 100 degrees apart. While Fahrenheit marks the freezing point of water at -32°F, Celsius marks it at 0°C.

U.S. Weights and Measures

In the United States, the metric system became the preferred system for weights and measures in trade in 1988. However, the metric system still competes with the Imperial system of measurements. Distances are measured by miles, not kilometers. Recipes measure volume and weight by cups and ounces. Football measures distance by the yard. And yet, our doctors and mechanics rely on the metric system. We also purchase bottles of soda and water by liter measurements. Other occupations that predominantly use the metric system include:

  • Manufacturing
  • Pharmacy
  • Transportation
  • Energy
  • Healthcare
  • Technology
  • Restaurants

On the 10th day of the 10th month, learn about this most accurate system of measurement.

HOW TO OBSERVE #NationalMetricDay

Celebrate the metric system by using it all day long. Test your skill and become accustomed to using metric units. Try these ways to celebrate:

  • Measure your speed and driving distance in kilometers.
  • Convert recipes or use recipes using the metric system.
  • Measure the temperature using Celsius.
  • Order beverages using the metric system.
  • Give measurements using centimeters.
  • Teach a metric unit on October 10.
  • Compare the Imperial System to the Metric System. What do you find?

While you’re measuring up, share how you use the metric system by using #NationalMetricDay on social media.


In 1977, the National Council of Teachers of Mathematics declared the week of May 9-13 as National Metric Week. Then in 1983, the council moved the observance to the week of October 10th to drive home the usefulness of the metric system. National Metric Day takes place on October 10th of that week.

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