## 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 391 feet per second into miles per hour we have to multiply 391 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

391 ft/s → V(mph)

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

V(mph) = 391 ft/s × 0.68181818181818 mph

V(mph) = 266.59090909091 mph

The final result is:

391 ft/s → 266.59090909091 mph

We conclude that 391 feet per second is equivalent to 266.59090909091 miles per hour:

391 feet per second = 266.59090909091 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 0.0037510656436488 × 391 feet per second.

Another way is saying that 391 feet per second is equal to 1 ÷ 0.0037510656436488 miles per hour.

## Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that three hundred ninety-one feet per second is approximately two hundred sixty-six point five nine one miles per hour:

391 ft/s ≅ 266.591 mph

An alternative is also that one mile per hour is approximately zero point zero zero four times three hundred ninety-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

feet per second (ft/s) miles per hour (mph)
392 feet per second 267.273 miles per hour
393 feet per second 267.955 miles per hour
394 feet per second 268.636 miles per hour
395 feet per second 269.318 miles per hour
396 feet per second 270 miles per hour
397 feet per second 270.682 miles per hour
398 feet per second 271.364 miles per hour
399 feet per second 272.045 miles per hour
400 feet per second 272.727 miles per hour
401 feet per second 273.409 miles per hour