21 centimeters in inches

Conversion formula
How to convert 21 centimeters to inches?

We know (by definition) that: $1\mathrm{cm}\approx 0.39370079\mathrm{in}$

We can set up a proportion to solve for the number of inches.

Now, we cross multiply to solve for our unknown $x$:

Conclusion: 21 ⁢ cm ≈ 8.267716590000001 ⁢ in

Conversion in the opposite direction

The inverse of the conversion factor is that 1 inch is equal to 0.120952380952381 times 21 centimeters.

It can also be expressed as: 21 centimeters is equal to $\frac{1}{\mathrm{0.120952380952381}}$ inches.

Approximation

An approximate numerical result would be: twenty-one centimeters is about eight point two six inches, or alternatively, a inch is about zero point one two times twenty-one centimeters.