21 inches in decimeters

Conversion formula
How to convert 21 inches to decimeters?

We know (by definition) that: $1\mathrm{in}=0.254\mathrm{dm}$

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

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

Conclusion: 21 ⁢ in = 5.334 ⁢ dm

Conversion in the opposite direction

The inverse of the conversion factor is that 1 decimeter is equal to 0.187476565429321 times 21 inches.

It can also be expressed as: 21 inches is equal to $\frac{1}{\mathrm{0.187476565429321}}$ decimeters.

Approximation

An approximate numerical result would be: twenty-one inches is about five point three three decimeters, or alternatively, a decimeter is about zero point one nine times twenty-one inches.