Length converters
Length is the simplest physical quantity to convert: every unit on this page is exactly a ratio of the SI meter. The 1959 international yard and pound agreement fixed inches at 25.4 mm exactly. The unit definitions are exact; displayed factors are rounded for readability, and calculations use IEEE 754 double-precision arithmetic.
Popular length conversions
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All length units
The 12 units below can be selected as source or target inside any length converter.
- Millimetersmm · Metric
- Centimeterscm · Metric
- Metersm · Metric
- Kilometerskm · Metric
- Inchesin · Imperial
- Feetft · Imperial
- Yardsyd · Imperial
- Milesmi · Imperial
- Nautical milesnmi · Other
- Light yearsly · Astronomical
- Parsecspc · Astronomical
- AngstromsÅ · Other
Length units in terms of the meter
Every length unit on Convertitive is defined as an exact ratio of the meter (m), the reference unit for this category. The table below shows what one of each unit equals in meters — the constant every converter on this page is built from.
| Unit | Symbol | 1 unit in meters |
|---|---|---|
| Millimeters | mm | 0.001 m |
| Centimeters | cm | 0.01 m |
| Meters | m | base unit |
| Kilometers | km | 1000 m |
| Inches | in | 0.0254 m |
| Feet | ft | 0.3048 m |
| Yards | yd | 0.9144 m |
| Miles | mi | 1609.34 m |
| Nautical miles | nmi | 1852 m |
| Light years | ly | 9.4607 × 10^15 m |
| Parsecs | pc | 3.0857 × 10^16 m |
| Angstroms | Å | 1.0000 × 10^−10 m |
To convert between any two units, Convertitive scales the input to meters using these factors and then back out to the target unit — so every result on this page traces to a single, exact definition rather than a chained approximation. Pick any pair above to see the formula, a 50-row reference table, and worked examples.