Conversion formula

The conversion factor from feet per second to miles per hour is 0.68181818181818, which means that 1 foot per second is equal to 0.68181818181818 miles per hour:

1 ft/s = 0.68181818181818 mph

To convert 8421 feet per second into miles per hour we have to multiply 8421 by the conversion factor in order to get the velocity amount from feet per second to miles per hour. We can also form a simple proportion to calculate the result:

1 ft/s → 0.68181818181818 mph

8421 ft/s → V_(mph)

Solve the above proportion to obtain the velocity V in miles per hour:

V_(mph) = 8421 ft/s × 0.68181818181818 mph

V_(mph) = 5741.5909090909 mph

The final result is:

8421 ft/s → 5741.5909090909 mph

We conclude that 8421 feet per second is equivalent to 5741.5909090909 miles per hour:

8421 feet per second = 5741.5909090909 miles per hour

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 mile per hour is equal to 0.00017416775521514 × 8421 feet per second.

Another way is saying that 8421 feet per second is equal to 1 ÷ 0.00017416775521514 miles per hour.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that eight thousand four hundred twenty-one feet per second is approximately five thousand seven hundred forty-one point five nine one miles per hour:

8421 ft/s ≅ 5741.591 mph

An alternative is also that one mile per hour is approximately zero times eight thousand four hundred twenty-one feet per second.

Conversion table

feet per second to miles per hour chart

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