Decorating your home requires lots of measurements. You need to know whether furniture will fit where you want it, how wide and long windows are for window treatments, and how much paint you need. Use the tips in the following list to help you decide what you need to measure and how to calculate quantities:
Find your room's overall square footage by multiplying the room's length by its width and squaring it (this is the area). You need this handy number for determining if a piece of furniture will fit in the room and for estimating quantities and prices.
Figure the amount of tile you need by dividing the width of the floor by the width of the tile (horizontal row) and the length of the floor by the height of the tile (vertical row). Buy up to 10 percent more tiles than you need, to allow for breakage and error.
Determine how many gallons of paint you need in order to paint a ceiling by measuring your floor's length and width, multiplying them, and then squaring the numbers. Divide this number by the spreading rate (see the paint can for this figure).
Establish how many gallons of paint you need for walls by adding the areas of the ceiling and walls. Divide this figure by the spreading rate (located on the can). If you're going from light to dark, double the amount (for a second coat). If the surface is porous, you may need 25 to 50 percent more paint — ask your store's paint pro for advice.
Measure the wall from floor to ceiling to determine wall space.
Average ceilings are about 8 feet high. Tall ceilings range from 10 to 12 feet or more. Low ceilings are anything under 8 feet. Use corrective decorating techniques by using the right color, texture, or pattern to make the most of space.
Be sure to add walk-around and breathing space between pieces of furniture to avoid clutter. Between chairs and sofas in seating groups, allow about 2 to 5 feet. Add up to a foot around your bed for bed-dressing and sheet changing. Leave 4 to 5 feet of clear walking space for traffic flow through rooms.