Conversion formula

The conversion factor from centimeters to millimeters is 10, which means that 1 centimeter is equal to 10 millimeters:

1 cm = 10 mm

To convert 420 centimeters into millimeters we have to multiply 420 by the conversion factor in order to get the length amount from centimeters to millimeters. We can also form a simple proportion to calculate the result:

1 cm → 10 mm

420 cm → L_(mm)

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

L_(mm) = 420 cm × 10 mm

L_(mm) = 4200 mm

The final result is:

420 cm → 4200 mm

We conclude that 420 centimeters is equivalent to 4200 millimeters:

420 centimeters = 4200 millimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 0.00023809523809524 × 420 centimeters.

Another way is saying that 420 centimeters is equal to 1 ÷ 0.00023809523809524 millimeters.

Approximate result

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

420 cm ≅ 4200 mm

An alternative is also that one millimeter is approximately zero times four hundred twenty centimeters.

Conversion table

centimeters to millimeters chart

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