The most common materials used for wall sheathing are either plywood or OSB (oriented strand board). It is easy to see the cost difference for one sheet, but sometimes you need to know the overall cost difference. And in general, OSB tends to be cheaper than plywood.

Example:

If you are sheathing a roof with a length of 40 feet 6 inches and a width of 18 feet 4 inches, this calculator will calculate the roof's square footage. It will then calculate the number of sheets it takes to cover the calculated area.

40' 6" * 18' 4" = 40.5 * 18.33 = 742.5 square feet
A 4' x 8' sheet = 32 square feet
742.5 ÷ 32 = 23.2

It will take 23.2 sheets to cover this section of the roof. And this is the number of sheets that determines the cost. There is no allowance for waste included.

The Calculator

1. length in feet and inches
2. width or height in feet and inches
3. Price of one sheet of 4' x 8' plywood
4. Price of one sheet of 4' x 8' OSB (oriented strand board)

The Results

1. square feet of wall or floor area
2. number of sheets needed
3. cost if plywood is used for sheathing
4. cost if OSB is used for sheathing