Conversion formula

The conversion factor from feet to kilometers is 0.0003048, which means that 1 foot is equal to 0.0003048 kilometers:

1 ft = 0.0003048 km

To convert 21 feet into kilometers we have to multiply 21 by the conversion factor in order to get the length amount from feet to kilometers. We can also form a simple proportion to calculate the result:

1 ft → 0.0003048 km

21 ft → L_(km)

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

L_(km) = 21 ft × 0.0003048 km

L_(km) = 0.0064008 km

The final result is:

21 ft → 0.0064008 km

We conclude that 21 feet is equivalent to 0.0064008 kilometers:

21 feet = 0.0064008 kilometers

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 kilometer is equal to 156.2304711911 × 21 feet.

Another way is saying that 21 feet is equal to 1 ÷ 156.2304711911 kilometers.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that twenty-one feet is approximately zero point zero zero six kilometers:

21 ft ≅ 0.006 km

An alternative is also that one kilometer is approximately one hundred fifty-six point two three times twenty-one feet.

Conversion table

feet to kilometers chart

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