How Do You Calculate the Volume of a Room?
To calculate the volume of any space, measure the length, width and height of the room. Multiply the length by the width and then by the height. Measuring the volume of nonrectangular rooms is a bit more complicated, requiring the division of the room into measurable sections.

Measure the room in feet
Take a tape measure and measure the length and the width of the room in feet. Measure the height of the ceiling as well. If the room is of an irregular shape, then measure the space and draw it out to scale on a piece of graph paper, using one square of the paper is equal to one inch or foot.

Section irregular rooms
Split the drawing of the room into subsections, mapping out square or rectangular sections first and then irregular sections separately. Label the dimensions of the sides of the sections.

Calculate the volume
Multiply the length of the room by the width to get the area of the room, then multiply this result by the room’s height to get the volume. For irregularly shaped rooms, calculate the volume of each subsection separately, and then add the totals together to get the total volume of the room.