How to Convert Metric Units of Length

The prefixes attached to metric units of length give you the key to converting among the units. Each prefix indicates how many meters are in one unit -- for example, a millimeter is 0.001 m, but a kilometer is 1,000 m. You can convert between any two metric units of length if you know the meaning of the prefixes.

Instructions

1

Calculate the conversion factor between the two units based on the prefixes. Common conversions include 10 mm per centimeter, 100 cm per meter and 1,000 m per kilometer. Divide the number of meters in the larger unit by the number of meters in the smaller unit to find other conversion factors.

2

Multiply the length by the conversion factor to convert from a larger to a smaller unit -- for example, multiply centimeters by 10 to get millimeters. Divide the length by the conversion factor to convert from a smaller to a larger unit -- for example, divide meters by 1,000 to get kilometers.

3

Write the value for the converted length followed by the correct unit.