## 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 421 knots into miles per hour we have to multiply 421 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

421 kt → V(mph)

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

V(mph) = 421 kt × 1.1507794480225 mph

V(mph) = 484.47814761749 mph

The final result is:

421 kt → 484.47814761749 mph

We conclude that 421 knots is equivalent to 484.47814761749 miles per hour:

421 knots = 484.47814761749 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 0.0020640765840888 × 421 knots.

Another way is saying that 421 knots is equal to 1 ÷ 0.0020640765840888 miles per hour.

## Approximate result

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

421 kt ≅ 484.478 mph

An alternative is also that one mile per hour is approximately zero point zero zero two times four hundred twenty-one 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)
422 knots 485.629 miles per hour
423 knots 486.78 miles per hour
424 knots 487.93 miles per hour
425 knots 489.081 miles per hour
426 knots 490.232 miles per hour
427 knots 491.383 miles per hour
428 knots 492.534 miles per hour
429 knots 493.684 miles per hour
430 knots 494.835 miles per hour
431 knots 495.986 miles per hour