How to Calculate a House Size

Go outside of your home along with an assistant or partner. Have your partner hold the end of the tape measure against the edge of a corner on one end of the home and then stretch the tape measure as far as it will go along that side. If the tape measure isn't long enough to extend along the entire side, mark the number of feet and inches where the tape ends and then have your partner advance her end of the tape to that mark. Continue until you reach the other end of the house.

Add together the total number of feet and inches you measured along that one side of the house and write that number down on a piece of paper, labeling it "Length."

Measure the perpendicular side of the house. If your first measurement went along the north and south direction, measure a side of the house that is running east and west. Measure this side in the same fashion as you did with steps 1 and 2, and write the total feet and inches on the paper, labeling it "Width."

Use your calculator and multiply the length times the width of the home. Write the result down on your paper. This is the total number of square feet for one floor of your home. Label this result as "Total Square Feet."

If you have a main level and a basement, you have two floors. In this case, double the number of "Total Square Feet." And if you have a basement, middle floor and second story floor, triple the number of "Total Square Feet."

Measure any protruding sections of the home separately, in the same way as you did above, such as porches and exterior wings. Add the square footage of those sections to the "Total Square Feet" result you obtained so that all home appendages are figured into your total.