## Conversion formula

The conversion factor from feet per second to kilometers per hour is 1.0972799999991, which means that 1 foot per second is equal to 1.0972799999991 kilometers per hour:

1 ft/s = 1.0972799999991 km/h

To convert 639 feet per second into kilometers per hour we have to multiply 639 by the conversion factor in order to get the velocity amount from feet per second to kilometers per hour. We can also form a simple proportion to calculate the result:

1 ft/s → 1.0972799999991 km/h

639 ft/s → V(km/h)

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

V(km/h) = 639 ft/s × 1.0972799999991 km/h

V(km/h) = 701.16191999944 km/h

The final result is:

639 ft/s → 701.16191999944 km/h

We conclude that 639 feet per second is equivalent to 701.16191999944 kilometers per hour:

639 feet per second = 701.16191999944 kilometers per hour

## Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 kilometer per hour is equal to 0.0014262040927733 × 639 feet per second.

Another way is saying that 639 feet per second is equal to 1 ÷ 0.0014262040927733 kilometers per hour.

## Approximate result

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

639 ft/s ≅ 701.162 km/h

An alternative is also that one kilometer per hour is approximately zero point zero zero one times six hundred thirty-nine feet per second.

## Conversion table

### feet per second to kilometers per hour chart

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

feet per second (ft/s) kilometers per hour (km/h)
640 feet per second 702.259 kilometers per hour
641 feet per second 703.356 kilometers per hour
642 feet per second 704.454 kilometers per hour
643 feet per second 705.551 kilometers per hour
644 feet per second 706.648 kilometers per hour
645 feet per second 707.746 kilometers per hour
646 feet per second 708.843 kilometers per hour
647 feet per second 709.94 kilometers per hour
648 feet per second 711.037 kilometers per hour
649 feet per second 712.135 kilometers per hour