Measure: Measure the length of the room
Measure the width of the room
Multiply length by width.
Always measure from wall to wall or from baseboard to baseboard.

Deduct: Deduct areas that are not going to be covered with hardwood floor.

Add: Add all the small sections like closets, laundry room, under the refrigerator and other small areas.

Conclude: Conclude by calculation of the measurement stage plus adding stage minus deduction stage.

Waste Factor: Add 10% to the total square footage in order to allow cuts and waste of the floor.