## Conversion formula

The conversion factor from knots to miles per hour is 1.1507794480225, which means that 1 knot is equal to 1.1507794480225 miles per hour:

1 kt = 1.1507794480225 mph

To convert 640 knots into miles per hour we have to multiply 640 by the conversion factor in order to get the velocity amount from knots to miles per hour. We can also form a simple proportion to calculate the result:

1 kt → 1.1507794480225 mph

640 kt → V(mph)

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

V(mph) = 640 kt × 1.1507794480225 mph

V(mph) = 736.49884673443 mph

The final result is:

640 kt → 736.49884673443 mph

We conclude that 640 knots is equivalent to 736.49884673443 miles per hour:

640 knots = 736.49884673443 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 0.0013577753779709 × 640 knots.

Another way is saying that 640 knots is equal to 1 ÷ 0.0013577753779709 miles per hour.

## Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that six hundred forty knots is approximately seven hundred thirty-six point four nine nine miles per hour:

640 kt ≅ 736.499 mph

An alternative is also that one mile per hour is approximately zero point zero zero one times six hundred forty knots.

## Conversion table

### knots to miles per hour chart

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

knots (kt) miles per hour (mph)
641 knots 737.65 miles per hour
642 knots 738.8 miles per hour
643 knots 739.951 miles per hour
644 knots 741.102 miles per hour
645 knots 742.253 miles per hour
646 knots 743.404 miles per hour
647 knots 744.554 miles per hour
648 knots 745.705 miles per hour
649 knots 746.856 miles per hour
650 knots 748.007 miles per hour