Metric units of length are used to measure how long, wide, or tall something is. The most common metric units of length are millimeters (mm), centimeters (cm), meters (m), and kilometers (km).
The metric system is based on powers of ten, making it easy to convert between units by multiplying or dividing by 10, 100, or 1,000.
To convert between metric units of length, move the decimal point to the right or left depending on whether you are changing to a smaller or larger unit.
A helpful way to remember: every step down is 10 times smaller, and every step up is 10 times larger.
This chart shows how metric units of length are related to each other. Use it to help you convert quickly and correctly.
Always label your answers with the correct unit. For example, “3 m” means 3 meters, not 3 centimeters or 3 millimeters.
When comparing metric lengths, make sure both measurements are in the same unit before deciding which is longer or shorter.
Always use the same unit before comparing. You can convert either measurement, but double-check your work.
Metric conversions help us measure accurately in science, travel, sports, and everyday life. Knowing how to convert makes problem solving easier.
Understanding metric units helps you think critically about measurements in the real world. Always check that your answer makes sense for what you are measuring.