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 20.5 centimeters into millimeters we have to multiply 20.5 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

20.5 cm → L_(mm)

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

L_(mm) = 20.5 cm × 10 mm

L_(mm) = 205 mm

The final result is:

20.5 cm → 205 mm

We conclude that 20.5 centimeters is equivalent to 205 millimeters:

20.5 centimeters = 205 millimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 0.0048780487804878 × 20.5 centimeters.

Another way is saying that 20.5 centimeters is equal to 1 ÷ 0.0048780487804878 millimeters.

Approximate result

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

20.5 cm ≅ 205 mm

An alternative is also that one millimeter is approximately zero point zero zero five times twenty point five 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