Converting inches to feet is a straightforward exercise. Problems can come up when you turn your inches into cubes. These two example problems will show how to convert in3 to ft3 and back again.
The conversion factor between in3 and ft3 is
1728 in3 = 1 ft3
How do you get this value? Start with the conversion between inches and feet.
12 inches = 1 foot
A cubic foot is a cube 1 foot wide, 1 foot tall, and 1 foot deep.
1 ft3 = 1 ft x 1 ft x 1ft
Substitute the conversion factor to get the inch units.
1 ft3 = (12 inches) x (12 inches) x (12 inches)
1 ft3 = 123 in3
1 ft3 = 1728 in3
in3 to ft3 Conversion Example Problem
Question: How many cubic feet are in 25,920 cubic inches?
Solution: Multiply the conversion factor to the 25,920 in3. Put the unit you want to be canceled out in the denominator.
This allows us to cancel out the unnecessary units, leaving only the unit we want.
25,920 in3 = 15 ft3
Answer: 25,920 cubic inches is equal to 15 cubic feet.
ft3 to in3 Conversion Example Problem
Question: How many cubic inches are in 4 cubic feet?
Solution: Multiply the conversion factor to the 4 ft3. Put the unit you want to cancel in the denominator.
Setting it up this way allows us to lose the unwanted ft3 unit.
4 ft3 = 6,912 in3
Answer: There are 6,912 cubic inches in 4 cubic feet.