Expert: Josh - 9/1/2009

Question
can you teach me how to convert 1 square kilometer to square meter?

Answer
Hi Aaron,

Consider the rectangular grids shown below.

A----------B----------C---
|          |          |
|          |          |
|          |          |
|          |          |
|          |          |
D----------E----------F---
|          |          |
|          |          |
|          |          |
|          |          |
|          |          |
G----------H----------I---
|          |          |

Each square (for example, ABED) represents an area of 1 square kilometer.
Side AB and AD are both 1 km in length.

Since 1 kilometer equals 1000 meters (the word "kilo" means multiply by a thousand), both dimensions |AB| and |AD| equal 1000 m.

The general formula for the area of a rectangle is Area = Length x Width.
Here, we can express this as
Area = |AB| x |AD|
    = 1000 [m] x 1000 [m] ....individual units are shown in square brackets.
    = 1000,0000 [m^2] ....here, area is measured in square meters.

So, 1 [km^2] = 1000,0000 [m^2].
One square kilometer equals one million square meters.