Conversion formula

The conversion factor from miles per hour to feet per second is 1.4666666666667, which means that 1 mile per hour is equal to 1.4666666666667 feet per second:

1 mph = 1.4666666666667 ft/s

To convert 685.6 miles per hour into feet per second we have to multiply 685.6 by the conversion factor in order to get the velocity amount from miles per hour to feet per second. We can also form a simple proportion to calculate the result:

1 mph → 1.4666666666667 ft/s

685.6 mph → V_(ft/s)

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

V_(ft/s) = 685.6 mph × 1.4666666666667 ft/s

V_(ft/s) = 1005.5466666667 ft/s

The final result is:

685.6 mph → 1005.5466666667 ft/s

We conclude that 685.6 miles per hour is equivalent to 1005.5466666667 feet per second:

685.6 miles per hour = 1005.5466666667 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 0.00099448392913971 × 685.6 miles per hour.

Another way is saying that 685.6 miles per hour is equal to 1 ÷ 0.00099448392913971 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 eighty-five point six miles per hour is approximately one thousand five point five four seven feet per second:

685.6 mph ≅ 1005.547 ft/s

An alternative is also that one foot per second is approximately zero point zero zero one times six hundred eighty-five point six miles per hour.

Conversion table

miles per hour to feet per second chart

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