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 840 centimeters into millimeters we have to multiply 840 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

840 cm → L_(mm)

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

L_(mm) = 840 cm × 10 mm

L_(mm) = 8400 mm

The final result is:

840 cm → 8400 mm

We conclude that 840 centimeters is equivalent to 8400 millimeters:

840 centimeters = 8400 millimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 0.00011904761904762 × 840 centimeters.

Another way is saying that 840 centimeters is equal to 1 ÷ 0.00011904761904762 millimeters.

Approximate result

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

840 cm ≅ 8400 mm

An alternative is also that one millimeter is approximately zero times eight hundred forty 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