With this information, you can calculate the quantity of feet per second 399 knots is equal to.

¿What is the inverse calculation between 1 foot per second and 399 knots?

Performing the inverse calculation of the relationship between units, we obtain that 1 foot per second is 0.0014849218 times 399 knots.

Which is the same to say that 399 knots is 673.43613 feet per second.

Three hundred ninety-nine knots equals to six hundred seventy-three feet per second. *Approximation

A foot per second is zero times three hundred ninety-nine knots. *Approximation