Article Ref: J-030

Weights and Measures Connection, Vol. 10, Issue 3 October 2020 Page 1

Final Notice on Deprecation of the U.S. Survey Foot Issued 

Byline: Elizabeth Benham

On October 5, 2020, it is planned that the National Institute of Standards and Technology (NIST) will publish a final 

notice titled “Deprecation of the United States (U.S.) Survey Foot” in the Federal Register. In the notice, NIST and 

the National Geodetic Survey (NGS), National Ocean Service (NOS), National Oceanic and Atmospheric 

Administration (NOAA), will announce they have taken collaborative action to deprecate the U.S. survey foot and 

require that its use for all applications in the United States, including surveying, mapping, and engineering, be 

discontinued after December 31, 2022. The goal of this action is to provide national uniformity of length measurement 

in an orderly fashion with minimum disruption, correcting a measurement dilemma that has persisted for over 60 

years. 

Beginning January 1, 2023, any measurement data derived from or published as a result of surveying, mapping, or 

any other activity within the U.S. that is expressed in terms of feet should only be based on the definition of one foot 

being equal to 0.3048 meter (exactly). This definition was named the “international foot” in a 1959 Federal Register 

Notice (24 FR 5348) that officially changed the foot definition for the U.S. In the 1959 notice, a second definition of 

the foot was named the “U.S. survey foot,” with a mandate that it be used only for geodetic surveying, and that it 

would ultimately be replaced by the international foot definition. 

With this final notice, the mandate to replace the U.S. survey foot with the international foot definition for all 

applications has been achieved, and after December 31, 2022, there will be one legal definition of the foot in the 

United States. The preferred term will be the “foot,” which is the name currently used in everyday measurements of 

length or distance. Because there are significant differences between traditional measurement systems (e.g., “Imperial” 

or “British” systems), NIST recommends use of the term “U.S. customary system of measurement” to describe the 

collection of non-SI measurement units currently used in the U.S. International foot definitions for traditional linear 

units, such as the cable’s length, chain, link, rod, and acre will also be announced in the notice. These changes will be 

reflected in the next editions of NIST Special Publication (SP) 811, “Guide for the Use of the International System of 

Units (SI),” and Handbooks under the sections on units and systems of measurement and conversion tables. 

NIST and NOAA encourage states and other government agencies, businesses, private and public organizations, and 

others potentially impacted by this change to take immediate steps for planning for the transition. Early action is 

important, since some changes can be time intensive, such as enacting state legislation and updating software, training 

materials, and relevant procedures. Recommended actions are published in the Federal Register Notice. The final 

Federal Register Notice will be available at this URL after October 5, 2020: www.nist.gov/pml/us-surveyfoot/frncitations. For more on the history of the U.S. survey foot to learn how the change will impact land surveys and 

mapping see NIST’s Frequently Asked Questions at www.nist.gov/pml/us-surveyfoot/frequently-asked-questionsfaqs. For more information contact Elizabeth Benham, NIST Metric Coordinator, at 301-975-3690 or at 

TheSI@nist.gov.