Knowing how to calculate the square feet of a box comes in handy for packing, moving or arranging your belongings. You might need to know how many boxes can fit in a room and will need to calculate the square feet of the room and the boxes themselves to deduce the answer. Houses are frequently priced based on the square-footage of the interior. Once you know how to calculate the square feet of an area you can apply it anywhere, as the formula is the same for any calculation of square area.
Measure the Length of the Box
Measure the length of the box, in feet, with yardstick or measuring tape. Write this number down.
Measure the Width of the Box
Measure the width of the box, in feet, writing this number down as well.
Multiply the Numbers Together
Multiply the two numbers together to get the square feet. For example, a box with a 4-foot side and a 6-foot side would measure 6 × 4 square feet, or 24 square feet.
TL;DR (Too Long; Didn't Read)
Apply any conversions that need to be made to the numbers – for instance, converting inches to feet, or feet to inches – to the input numbers instead of the final product for consistency.
Each foot contains 12 inches. Therefore, if you've measured in feet and want to convert to inches, simply take your initial dimensions (in feet) and multiply them by 12. Likewise, if you've measured in inches and want to convert to feet, divide your initial dimensions by 12.