## Conversion formula

The conversion factor from kilometers to millimeters is 1000000, which means that 1 kilometer is equal to 1000000 millimeters:

1 km = 1000000 mm

To convert 4.2 kilometers into millimeters we have to multiply 4.2 by the conversion factor in order to get the length amount from kilometers to millimeters. We can also form a simple proportion to calculate the result:

1 km → 1000000 mm

4.2 km → L(mm)

Solve the above proportion to obtain the length L in millimeters:

L(mm) = 4.2 km × 1000000 mm

L(mm) = 4200000 mm

The final result is:

4.2 km → 4200000 mm

We conclude that 4.2 kilometers is equivalent to 4200000 millimeters:

4.2 kilometers = 4200000 millimeters

## Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 2.3809523809524E-7 × 4.2 kilometers.

Another way is saying that 4.2 kilometers is equal to 1 ÷ 2.3809523809524E-7 millimeters.

## Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that four point two kilometers is approximately four million two hundred thousand millimeters:

4.2 km ≅ 4200000 mm

An alternative is also that one millimeter is approximately zero times four point two kilometers.

## Conversion table

### kilometers to millimeters chart

For quick reference purposes, below is the conversion table you can use to convert from kilometers to millimeters

kilometers (km) millimeters (mm)
5.2 kilometers 5200000 millimeters
6.2 kilometers 6200000 millimeters
7.2 kilometers 7200000 millimeters
8.2 kilometers 8200000 millimeters
9.2 kilometers 9200000 millimeters
10.2 kilometers 10200000 millimeters
11.2 kilometers 11200000 millimeters
12.2 kilometers 12200000 millimeters
13.2 kilometers 13200000 millimeters
14.2 kilometers 14200000 millimeters