With this information, you can calculate the quantity of knots 21 miles per hour is equal to.
¿What is the inverse calculation between 1 knot and 21 miles per hour?
Performing the inverse calculation of the relationship between units, we obtain that 1 knot is 0.054799021 times 21 miles per hour.
Which is the same to say that 21 miles per hour is 18.248501 knots.
Twenty-one miles per hour equals to eighteen knots. *Approximation
A knot is zero times twenty-one miles per hour. *Approximation
