Calculate square footage from a length and width in any common unit. Add a quantity for repeated areas, a waste factor, and an optional price to get the area and cost.
Usage Tip
Measure twice and to the widest points. For flooring or tile, add the waste factor here so the area you take to the store already includes the cushion.
Total = Area × number of areas
With waste = Total × (1 + waste%)
For rooms that are not simple rectangles, split them into rectangles, find each area, and add them up.
Add a waste factor for materials cut to fit — commonly about 10% for flooring and tile, more for diagonal or patterned layouts.
Materials sold by the box or sheet still need rounding up to whole units after you have the area.
