With this information, you can calculate the quantity of kilometers per hour 21 knots is equal to.

¿What is the inverse calculation between 1 kilometer per hour and 21 knots?

Performing the inverse calculation of the relationship between units, we obtain that 1 kilometer per hour is 0.025712229 times 21 knots.

Which is the same to say that 21 knots is 38.892 kilometers per hour.

Twenty-one knots equals to thirty-eight kilometers per hour. *Approximation

A kilometer per hour is zero times twenty-one knots. *Approximation