From meters (m)
- Meters to Kilometersm → km
- Meters to Centimetersm → cm
- Meters to Milesm → mi
- Meters to Feetm → ft
Length conversion family
Length unit conversions
Length is the SI base quantity with dimension L; the metre (m) is its SI base unit.
Five named units
Unit and factor reference
| Unit | Symbol | Factor to base | Relationship | Definition and variant |
|---|---|---|---|---|
| meter | m | 1 | defined | The meter is the U.S. English spelling of the metre, the SI base unit of length, defined through the fixed numerical value of the speed of light in vacuum. The base factor is exactly 1 by the family base-unit choice. |
| kilometer | km | 1000 | exact | A kilometer is the SI decimal multiple formed by applying kilo (10³) to the meter: 1 km = 1000 m. The decimal-prefix relationship is exact. |
| centimeter | cm | 0.01 | exact | A centimeter is the SI decimal submultiple formed by applying centi (10⁻²) to the meter: 1 cm = 0.01 m. The decimal-prefix relationship is exact. |
| mile | mi | 1609.344 | defined | This mile is the international mile of 5280 international feet: 1 mi = 1609.344 m exactly. Named variant: International mile based on the international foot; not the legacy U.S. survey mile or nautical mile. The terminating base factor is exact for the international mile. |
| foot | ft | 0.3048 | defined | This foot is the international foot, defined as exactly 0.3048 meter. Named variant: International foot; the U.S. survey foot (1200/3937 m) is a distinct legacy unit. The terminating base factor is exact. |
Every ordered pair
All 20 length calculators
From kilometers (km)
- Kilometers to Meterskm → m
- Kilometers to Centimeterskm → cm
- Kilometers to Mileskm → mi
- Kilometers to Feetkm → ft
From centimeters (cm)
- Centimeters to Meterscm → m
- Centimeters to Kilometerscm → km
- Centimeters to Milescm → mi
- Centimeters to Feetcm → ft
From miles (mi)
- Miles to Metersmi → m
- Miles to Kilometersmi → km
- Miles to Centimetersmi → cm
- Miles to Feetmi → ft
From feet (ft)
- Feet to Metersft → m
- Feet to Kilometersft → km
- Feet to Centimetersft → cm
- Feet to Milesft → mi
Evidence and review status
This family is machine-reviewed-pending-human. Automated checks verify structure, factor parity and source references; they do not constitute human or specialist approval.
Family assumptions and limits
- This family converts non-negative length magnitudes; it does not infer direction, path, displacement, or measurement uncertainty.
- Foot and mile mean the international foot and international mile. U.S. survey-foot values are outside this family and can differ in legacy geodetic records.
- A conversion does not add significant figures to the source measurement.
Authoritative references
- The International System of Units (SI), 9th edition, version 4.01; Bureau International des Poids et Mesures; Sections 2.3.1 and 3; metre definition on p. 127 (PDF p. 16) and SI prefixes in Table 7 on p. 138 (PDF p. 27).; accessed 2026-08-07
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement; National Institute of Standards and Technology; Pages C-4 to C-5 and C-9 to C-10; metric length table, 1 mile = 5,280 feet, and exact international-foot relationships including 1 ft = 0.3048 m and 1 mi = 1609.344 m.; accessed 2026-08-07