For instance, if the volume is 6,912 cubic inches, divide 6,912 by 1,728, which is 4. So the volume is 4 cubic feet.

For instance, if the volume of your shape or space is 1,000 cubic yards, multiply 1,000 by 27, which equals 27,000 cubic feet.

For example, if the volume of your shape or space is 500,000 cubic inches, divide 500,000 by 28,316. 85. This is equal to 17. 6573312356, which can be rounded to 17. 66 cubic feet.

For example, if your space or shape has a volume measurement of 450 cubic meters, multiply 450 by 35. 31 for a result of 15,889. 50 cubic feet.

Use the same units for each side of the prism. Ideally, measure in feet so the result is in cubic feet. Otherwise, you can convert the units once you find the volume.

For example, say the length of a room you’re measuring is 10 feet and the width is 5 feet. Multiply 10 feet by 5 feet, which is 50 feet2. The feet are squared because you are multiplying not just the numbers but the units as well.

For example, if the height of the room is 15 feet, multiply 15 by 50 feet2 (the area of the base of the room from the previous step). The total volume of the room is 750 feet3.

Measure the space or shape in feet or convert all of the units to feet before beginning so your answer is in cubic feet. Otherwise, convert the units to cubic feet when you know the volume.

For instance, if you’re digging a hole for a post and the radius of the post is 0. 5 feet, multiply 0. 5 by 0. 5 to get 0. 25 feet2. Then, multiply 0. 25 feet2 by 3. 14, which is equal to 0. 785 feet2. Remember that the units for the radius are squared because you’re multiplying them together the same way you multiply the numbers together. If you know the diameter of the circle instead of the radius, simply divide the diameter by 2 to get the radius. So, the radius of a circle with a diameter of 12 would be 6.

For instance, take the area from the last step, which is 0. 785 feet2. If you need the hole for the post to be 2 feet deep, the height would be 2, so multiply 2 by 0. 785 feet2 to get 1. 57 feet3 which is the volume of the post hole.