Framing

Exterior Wall Sheathing

To calculate the number of sheets needed to cover a wall, you need to know the wall's square footage.

The square footage of a wall divided by the square footage of the sheathing (one 4ft x 8ft sheet = 32 square feet) equals the number of sheets needed.

If you have a small opening on your wall, then ignore that. Run the sheathing through and cut out the opening afterwards.

For larger openings in the wall that don't need sheathing, subtract the square footage of these openings from the total square footage. However, you may waste some of the sheathing material, and you may need more than the calculated amount.

Sheathing + Cost Calculator

Calculation;

enter the length of the wall in feet and inches
the height of the wall in feet and inches
the combined square footage of the wall openings you wish to subtract
the cost of one sheet of plywood or OSB

Results;

the total square footage of the wall
the square footage of the wall minus the square footage of subtracted openings
the number of sheets needed to cover the wall
the cost of the sheathing material (based on a 4ft x 8ft sheet size)

Example calculation for calculating the number of sheets needed

wall length = 12 feet
wall height = 8 feet
size of the plywood = 4ft x 8ft

Calculate the square footage of the wall by multiplying the wall length by its height;

8 x 12' = 96

This wall has a square footage of 96 square feet

Calculate the amount of square feet in a 4ft x 8ft sheet;

4 x 8 = 32

A 4 ft x 8 ft sheet of plywood has 32 square feet of area

Divide the walls square footage by the amount of square feet of one sheet of plywood;

96 ÷ 32 = 3

For this wall you will need 3 sheets of 4ft x 8ft plywood.