With this information, you can calculate the quantity of square kilometers 21 hectares is equal to.

¿What is the inverse calculation between 1 square kilometer and 21 hectares?

Performing the inverse calculation of the relationship between units, we obtain that 1 square kilometer is 4.7619048 times 21 hectares.

Which is the same to say that 21 hectares is 0.21 square kilometers.

Twenty-one hectares equals to zero square kilometers. *Approximation

A square kilometer is four times twenty-one hectares. *Approximation