You may find you need to determine the size of your home, whether for planning an addition or for planning a more efficient use of your available floor space. Home sizes are stated in total number of metres squared or square feet of all floors combined. To find the total area of your home, you must have accurate measurements and also have the right mathematical formula to arrive at the result.

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 metres and centimetres 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 metres and centimetres you measured along that one side of the house and write that number down on a piece of paper, labelling 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 metres and centimetres on the paper, labelling 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 metres squared for one floor of your home. Label this result as "Total Metres Squared."

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

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 metres of those sections to the "Total Metres Squared" result you obtained so that all home appendages are figured into your total.