Measure the length, width, and height in feet
Multiply length × width × height
If measurements are in inches, divide each by 12 first
If measurements are in yards, multiply each by 3 to convert to feet first
Use the formula: cubic feet = L × W × H
For irregular shapes, break the space into smaller rectangular sections and add the cubic feet together
For boxes, use the inside dimensions
Round to the nearest hundredth if needed