Plywood Calculator

Use our handy plywood calculator to instantly determine how much plywood you need for a project and total costs.

How to use this plywood sheet calculator

Our plywood calculator estimates the number of sheets of plywood needed based on the surface area to be covered and the size of each sheet of plywood. Start by entering the length and width of the surface area to be covered, plus a percentage amount of waste. Then, enter the plywood sheet size, which is frequently 4 ft. wide by 8 ft. long. The total number of plywood sheets is then calculated. Lastly, enter the cost per sheet to estimate the total project material cost.

Calculating how much plywood you need

Determining how much plywood you need is reasonably straightforward, as follows.

First, we need to calculate how much surface area needs to be covered, plus the amount of waste. The below formula calculates the total surface area to be covered plus waste.

(Surface Length x Surface Width) x (1 + % Waste) = Total Square Footage Covered

Once calculating the total square footage covered, calculate the number of square feet for each plywood sheet.

Plywood Width x Plywood Length = Square Feet Per Plywood Sheet

Since we have the total surface area and square footage for each plywood sheet, we can calculate the number of sheets needed with the formula below.

Total Square Footage Covered ÷ Square Feet Per Plywood Sheet = Plywood Sheets Needed

Example plywood sheet calculation

Let’s use an example to demonstrate how much plywood you need for a project and how to calculate it. In our example, we’ll cover a 20 ft. by 8 ft. wall with 4×8 sheets of plywood. 15% of the material is waste.

The total square footage covered is calculated as (20 x 8) x (1.15) = 184.

Each sheet of 4×8 plywood covers 32 ft., calculated as 4 x 8.

Now, we divide 184 by 32 to get a result of 5.75 sheets of plywood needed. In practice, round up to the next whole number, 6 in our example, to get the final result for the number of plywood sheets needed.

This plywood calculator also estimates the total cost based on the sheets of plywood needed and the cost per sheet. For example, the total cost would be $150 that costs $25 per sheet, or $25 x 6.

Projects to use this calculator for

A plywood sheet calculator can calculate more than just plywood material needs and is just as useful as an OSB calculator, MDF calculator, sheathing calculator, or roof plywood calculator.

The calculations are the same since the intent is to cover a surface, such as interior walls, exterior walls, subfloors, and rooftops, with sheet goods.

How many square feet is a 4×8?

A 4×8 is 32 square feet, as calculated by multiplying 4 by 8. Plywood, MDF, OSB, and other sheet goods also come in other standard sizes. Below, we provide a table to quickly determine the square footage for various sheet goods in common sizes.

SizeSquare Feet

While plywood sizing is a standardized industry measurement, sheet goods and woods are measured differently. For example, some woods are measured in linear feet whereas specialty woods are measured in board feet.


  • What are the standard plywood sizes?

    Plywood is most frequently sold as a 4×8 or 5×5 sheets. Select specialty plywoods come in sizes such as 2×2, 2×4, and 4×4 dimensions. Utility plywood comes in sizes including 4×10 and longer.

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Nathan Hamilton
Nathan Hamilton is the founder of DIY Gear Reviews and a recognized expert in the home and DIY space. He has over 200 bylines covering topics such as power tools, hand tools, and woodworking. Nathan is the strategic director for DIY Gear Reviews, deciding everything from the content covered to designing the testing methodologies for lab-tested reviews. He can be emailed at

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