Conversion formula

The conversion factor from miles to kilometers is 1.609344, which means that 1 mile is equal to 1.609344 kilometers:

1 mi = 1.609344 km

To convert 40 miles into kilometers we have to multiply 40 by the conversion factor in order to get the length amount from miles to kilometers. We can also form a simple proportion to calculate the result:

1 mi → 1.609344 km

40 mi → L_(km)

Solve the above proportion to obtain the length L in kilometers:

L_(km) = 40 mi × 1.609344 km

L_(km) = 64.37376 km

The final result is:

40 mi → 64.37376 km

We conclude that 40 miles is equivalent to 64.37376 kilometers:

40 miles = 64.37376 kilometers

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 kilometer is equal to 0.015534279805933 × 40 miles.

Another way is saying that 40 miles is equal to 1 ÷ 0.015534279805933 kilometers.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that forty miles is approximately sixty-four point three seven four kilometers:

40 mi ≅ 64.374 km

An alternative is also that one kilometer is approximately zero point zero one six times forty miles.

Conversion table

miles to kilometers chart

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