Home > Conversion > Length > km to mm

Convert km to mm

Interactive kilometers to millimeters conversion tool

The km to mm converter below can be used to quickly and easily convert kilometers to millimeters. Simply enter the number of kilometers you want to convert and the calculator will output the corresponding value in millimeters.

What is the conversion factor between kilometers and millimeters?

A conversion factor is used to change the units of a measured quantity without changing its value. It represents the ratio (or fraction) that expresses the relationship between two different units. A conversion factor is always equal to 1.

The relationship between kilometers and millimeters is 1e+6, such as:

Following the formula above, we can see that there are 1e+6 millimeters for every kilometer, and for every millimeter, there are 11e+6 kilometers (1e-6 km).

To convert from kilometers to millimeters, we turn our formula into a conversion factor that is equal to 1.

Both these fractions are equal to 1. The numerator and the denominator are equivalent, they are just expressed in different units.

Because we are converting from kilometer to millimeter, we will use the first fraction: 1e+6 mm1 km so that kilometers are canceled out. We then multiply the value in kilometers by this fraction to get the result in millimeters (see example).

Note that km is in the denominator (bottom) of the conversion factor. This is important, you always want to have the unit you are converting from at the bottom and the unit you are converting to in the numerator (top).

You will find below how to use this ratio to convert from km to mm. Just remember for now that the conversion factor for converting from kilometers to millimeters is:

Which is bigger, a kilometer or a millimeter?

When it comes to measurements, there can be some confusion over which is bigger, a kilometer or an millimeter. To find out which one is larger, we must first convert one unit to the other and then compare them.

• 1 km = 1e+6 mm
• 1e+6 millimeters is bigger than 1 millimeter.
• 1 kilometer is, therefore, bigger than 1 millimeter.
• To be more specific, a millimeter is 1e+6 times smaller than a kilometer.

kilometers to millimeters conversion table

How to convert kilometers to millimeters?

Multiplying any value by 1 will get you the same value back. You can do that one time or multiple times.

For example:

• 17 x 1 = 17
• 854 x 1 x 1 x 1 = 854

Multiplying by 1 is the first step in any unit conversion problem. The second step is to replace the number 1 with the conversion factor that is also equal to 1.

For example, if we want to convert 10 kilometers into millimeters we multiply 10 km by the conversion factor of 1e+6 mm1 km

By replacing the number 1 with the conversion factor, kilometers are canceled out and we get the result in millimeters. And since the conversion factor is equal to 1, multiplying it with the original value won't change its magnitude and will only change its unit.

Based on this, we can conclude that 10 kilometers are equal to 1e+7 millimeters.

Remember:

• When converting from kilometers to millimeters, we use 1e+6 mm1 km as a conversion factor.

Practice: kilometers to millimeters conversion

Try answering the following questions without using our custom conversion calculator. Knowing how to convert manually between kilometers and millimeters could prove to be useful, so give it a shot. Once you are confident you can convert kilometers to millimeters, there is no harm then in taking full advantage of the tools available to you.

How to convert 79 kilometers to millimeters?

We multiply 79 by the factor of 1

We replace the number 1 with the conversion factor for kilometers to millimeters

We multiply 79 kilometers by the conversion factor. Having kilometers in the denominator allows us to cancel out the undesired units (km) leaving only millimeters in the final result.

Answer: There are 7.9e+7 millimeters in 79 kilometers

How many millimeters are in 330 kilometers?

Multiply 330 by the conversion factor. Make sure the unwanted unit (km) is in the denominator.

This allows us to cancel out the kilometers (km) and leave the millimeters (mm)

Answer: There are 3.3e+8 millimeters in 330 kilometers

millimeters to kilometers conversion

• 1 mm = 11e+6 km = 1e-6 km
• To convert from millimeters to kilometers use our mm to km converter

kilometers conversion

millimeters conversion

length conversion