Length converter
Converts lengths and distances: m, km, ft, US survey ft, in, yd, mi, and NM.
5,280 ft is 1,609.344 m.
- Input
Provenance
- Computed by
- units.length.convert 1.0.0, core 0.1.0
- Model
- Exact unit definitions
- Accuracy
- Exact to double precision: each conversion is one correctly rounded ratio of exact definitions
- Notes
- None
- Cites
- National Institute of Standards and Technology, Guide for the Use of the International System of Units (SI), NIST Special Publication 811; National Institute of Standards and Technology, Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices, NIST Handbook 44; National Institute of Standards and Technology and National Oceanic and Atmospheric Administration, Deprecation of the United States (U.S.) Survey Foot, 84 FR 60101
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Exact unit definitions
Accuracy: Exact to double precision: each conversion is one correctly rounded ratio of exact definitions
When to use this: Use this for any distance that has to move between systems: a runway length in feet against a chart in meters, a leg in nautical miles against a road distance in statute miles, a survey dimension in feet against a design in millimeters. The two kinds of foot are both here and kept apart, which matters more than it sounds: US survey feet and international feet differ by two parts per million, which is a tenth of a millimeter over a meter and two feet across a state plane zone.
Limitations: A conversion is exact and a measurement is not, so this changes the unit and never improves the number: 5,280 ft becomes 1,609.344 m exactly, but if the 5,280 was good to a foot the answer is good to 0.3 m. The US survey foot was withdrawn for new work at the end of 2022 and is kept here only for reading existing records; a value carrying it is flagged. Nautical miles are the international 1,852 m exactly, not the old British or US ones, and the statute mile is the international one -- an old chart may mean neither.
Worked example: 5,280 ft in meters. Source: Exact unit definitions (NIST SP 811 Appendix B). It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.
You enter
- To unit
- m
- Value
- 5280 ft
You get
- Converted
- 1,609.344 m
- Input
- 5,280 ft
Review: Not yet independently reviewed by a metrologist.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 135 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, National Institute of Standards and Technology, 2008 edition. Appendix B.8, Factors for units listed alphabetically.
- Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices, NIST Handbook 44, National Institute of Standards and Technology, 2026 edition. Appendix C, General Tables of Units of Measurement.
- Deprecation of the United States (U.S.) Survey Foot, 84 FR 60101, National Institute of Standards and Technology and National Oceanic and Atmospheric Administration, Federal Register notice, October 5, 2020 final (85 FR 62698). Effective January 1, 2023.