# Metric Length

We can measure how long things are, or how tall, or how far apart they are. Those are are all examples of length measurements.

Example: This fork is 20 centimeters long

These are the most common measurements:

**Millimeters****Centimeters****Meters****Kilometers**

Small units of length are called **millimeters**.

A millimeter is about the **thickness of a plastic id card** (or credit card).

Or about the thickness of 10 sheets of paper on top of each other.

This is a very small measurement!

When we have 10 millimeters, it can be called a **centimeter**.

1 centimeter = 10 millimeters

A fingernail is about **one centimeter wide**.

Two tape measures, one in mm, the other in cm

We can use millimeters or centimeters to measure how tall we are, or how wide a table is, but to measure the length of football field it is better to use **meters**.

A **meter** is equal to 100 centimeters.

1 meter = 100 centimeters

The length of this guitar is about 1 meter

Meters might be used to measure the length of a house, or the size of a playground.

And because a centimeter is 10 millimeters:

1 meter = 1000 millimeters

A **kilometer** is equal to 1000 meters.

When we need to get from one place to another, we measure the distance using **kilometers**.

The distance from one city to another or how far a plane travels can be measured using kilometers.

Final thoughts about measuring length:

1 centimeter = 10 millimeters

1 meter = 100 centimeters

1 kilometer = 1000 meters

## Lots of Examples

A centimeter (cm) is about:

- about as long as a staple
- the width of a highlighter
- the diameter of a belly button
- the width of 5 CD's stacked on top of each other
- the thickness of a notepad.
- the radius (half the diameter) of a US penny

A meter (m) is about:

- a little more than a yard (1 yard is exactly 0.9144 meters)
- the width of a doorway (most doorways are about 0.8 to 0.9 m)
- half the length of a bed
- the width of a large fridge
- the height of a countertop
- four rungs up a ladder
- five steps up a staircase
- the depth of the shallow end of a swimming pool
- the width of a dining table
- the height of a 5 year old
- shoulder to opposite wrist of an adult
- outstreched arms of a child
- waist high on an adult

One meter equals roughly one long step of an adult man. |

A kilometer (km) is about:

- a little over half a mile
- a quarter of the average depth of the ocean

One kilometer equals about 12 minutes' walk. |

Also see Lengths From Very Small to Very Large |