The two United States federal agencies, National Institute of Standards and Technology (NIST) and National Oceanic and Atmospheric Administration (NOAA) retired use of the “U.S. survey foot” on December 31, 2022.
1 International foot = 0.3048 meters
1 US survey foot = 0.3048006096 meters
To most people, the difference is barely discernible and equates to approximately one-eighth of an inch per mile. However, surveyors who measure over long distances, the impact can be significant. The difference starts showing up on 2nd decimal place for lengths over 10,000. If US foot was used to survey distances, apply a multiplication factor of 1.000002 to convert to International foot.
Length(meters) | USS-FT | Int-FT | | USS-FT | Int-FT |
1 | 3.280833333 | 3.280839895 | | 1.00 | 1.00 |
100 | 328.0833333 | 328.0839895 | | 100.00 | 100.00 |
1,000 | 3280.833333 | 3280.839895 | | 1,000.00 | 1,000.00 |
10,000 | 32808.33333 | 32808.39895 | | 10,000.00 | 10,000.02 |
100,000 | 328083.3333 | 328083.9895 | | 100,000.00 | 100,000.20 |
ArcGIS Pro, starting at version 3.0 has both distinct foot definitions and will continue to support US survey foot in the foreseeable future. It is up to users to review their data, organizational standards and make decisions that best serve their business/compliance requirements.
Further reads at:
