Unit Converter
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 21 centimeters into millimeters we have to multiply 21 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
21 cm → L(mm)
Solve the above proportion to obtain the length L in millimeters:
L(mm) = 21 cm × 10 mm
L(mm) = 210 mm
The final result is:
21 cm → 210 mm
We conclude that 21 centimeters is equivalent to 210 millimeters:
21 centimeters = 210 millimeters
Alternative conversion
We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 0.0047619047619048 × 21 centimeters.
Another way is saying that 21 centimeters is equal to 1 ÷ 0.0047619047619048 millimeters.
Approximate result
For practical purposes we can round our final result to an approximate numerical value. We can say that twenty-one centimeters is approximately two hundred ten millimeters:
21 cm ≅ 210 mm
An alternative is also that one millimeter is approximately zero point zero zero five times twenty-one 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
centimeters (cm) | millimeters (mm) |
---|---|
22 centimeters | 220 millimeters |
23 centimeters | 230 millimeters |
24 centimeters | 240 millimeters |
25 centimeters | 250 millimeters |
26 centimeters | 260 millimeters |
27 centimeters | 270 millimeters |
28 centimeters | 280 millimeters |
29 centimeters | 290 millimeters |
30 centimeters | 300 millimeters |
31 centimeters | 310 millimeters |