With this information, you can calculate the quantity of feet per second 821 knots is equal to.

¿What is the inverse calculation between 1 foot per second and 821 knots?

Performing the inverse calculation of the relationship between units, we obtain that 1 foot per second is 0.00072166115 times 821 knots.

Which is the same to say that 821 knots is 1385.6919 feet per second.

Eight hundred twenty-one knots equals to one thousand three hundred eighty-five feet per second. *Approximation

A foot per second is zero times eight hundred twenty-one knots. *Approximation