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 640.9 knots into feet per second we have to multiply 640.9 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

640.9 kt → V_(ft/s)

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

V_(ft/s) = 640.9 kt × 1.6878098570997 ft/s

V_(ft/s) = 1081.7173374152 ft/s

The final result is:

640.9 kt → 1081.7173374152 ft/s

We conclude that 640.9 knots is equivalent to 1081.7173374152 feet per second:

640.9 knots = 1081.7173374152 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 0.00092445592338338 × 640.9 knots.

Another way is saying that 640.9 knots is equal to 1 ÷ 0.00092445592338338 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 forty point nine knots is approximately one thousand eighty-one point seven one seven feet per second:

640.9 kt ≅ 1081.717 ft/s

An alternative is also that one foot per second is approximately zero point zero zero one times six hundred forty 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