To convert millimeters to meters (mm to m), multiply by 0.001. 1 millimeter equals 0.001 m, about 17% of a grain of rice.
| millimeters | meters |
|---|---|
| 1 millimeter | 0.001 m |
| 2 millimeters | 0.002 m |
| 5 millimeters | 0.005 m |
| 10 millimeters | 0.01 m |
| 25 millimeters | 0.025 m |
| 50 millimeters | 0.05 m |
| 100 millimeters | 0.1 m |
| 250 millimeters | 0.25 m |
| 500 millimeters | 0.5 m |
| 1000 millimeters | 1 m |
Definition: 1/1000 of a meter - the same "milli" prefix as milliliter or milligram.
History: Like the centimeter, it arrived as part of the same 1790s French decimal system, built specifically to make precise, small-scale measurement simple - no more converting between competing local systems of inches, lines, and points.
Current use: Engineering tolerances, screen and camera specs, and rainfall measurements - which is why weather reports outside the US say "20mm of rain" rather than inches.
Definition: The base unit of length in the metric system - every other metric length (km, cm, mm) is just meters multiplied or divided by a power of ten.
History: Born out of the French Revolution's push to replace a chaotic patchwork of local, often royally-defined units with something rational and universal. In 1793, French scientists defined the meter as one ten-millionth of the distance from the North Pole to the Equator, measured along the meridian running through Paris - they actually sent surveyors out to physically measure the distance between Dunkirk and Barcelona to calculate it, a project that took years longer than planned. Today the meter is defined by something far more precise and impossible to argue with: the distance light travels in a tiny, fixed fraction of a second.
Current use: The foundation of virtually every length measurement outside the US - room dimensions, building heights, and race distances (measured in km) all build on it.