How do you calculate the cubic feet of a room that is 10 feet by 12 feet by 8 feet high?

Wouldn't that be 6 times 11.5 times 8 = 552 cubic feet. You need to measure the length and width of the room. Using a retractable measuring tape, or laser measuring tool, measure the room from end to end in one direction, an d in the other. Draw a rectangle on the paper and record the measurement of each wall on the paper. If your room is rectangle, then you are done. If your room is odd shaped, you will also need to measure odd corners and walls.