Conversion formula

The conversion factor from knots to feet per second is 1.6878098570997, which means that 1 knot is equal to 1.6878098570997 feet per second:

1 kt = 1.6878098570997 ft/s

To convert 639.9 knots into feet per second we have to multiply 639.9 by the conversion factor in order to get the velocity amount from knots to feet per second. We can also form a simple proportion to calculate the result:

1 kt → 1.6878098570997 ft/s

639.9 kt → V_(ft/s)

Solve the above proportion to obtain the velocity V in feet per second:

V_(ft/s) = 639.9 kt × 1.6878098570997 ft/s

V_(ft/s) = 1080.0295275581 ft/s

The final result is:

639.9 kt → 1080.0295275581 ft/s

We conclude that 639.9 knots is equivalent to 1080.0295275581 feet per second:

639.9 knots = 1080.0295275581 feet per second

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 foot per second is equal to 0.00092590061149618 × 639.9 knots.

Another way is saying that 639.9 knots is equal to 1 ÷ 0.00092590061149618 feet per second.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that six hundred thirty-nine point nine knots is approximately one thousand eighty point zero three feet per second:

639.9 kt ≅ 1080.03 ft/s

An alternative is also that one foot per second is approximately zero point zero zero one times six hundred thirty-nine point nine knots.

Conversion table

knots to feet per second chart

For quick reference purposes, below is the conversion table you can use to convert from knots to feet per second