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