Conversion formula

The conversion factor from feet to inches is 12, which means that 1 foot is equal to 12 inches:

1 ft = 12 in

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

1 ft → 12 in

21 ft → L_(in)

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

L_(in) = 21 ft × 12 in

L_(in) = 252 in

The final result is:

21 ft → 252 in

We conclude that 21 feet is equivalent to 252 inches:

21 feet = 252 inches

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 inch is equal to 0.003968253968254 × 21 feet.

Another way is saying that 21 feet is equal to 1 ÷ 0.003968253968254 inches.

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 two hundred fifty-two inches:

21 ft ≅ 252 in

An alternative is also that one inch is approximately zero point zero zero four times twenty-one feet.

Conversion table

feet to inches chart

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