Subfloor Cost

The Subflooring Cost calculator computes the number of 4x8 sheets (e.g. plywood or OSB) required for a floor, sub-floor or deck, and uses the unit price of a 4x8 sheet to compute the cost estimate.

INSTRUCTIONS: Choose and enter the following:

• (W) Floor Width
• (L) Floor Length
• (uP)  Unit price of 4x8 sheet (default: 5/8" 4x8 below)

Total Cost (TC): The calculator will then compute the total cost of sub-flooring boards in U.S. dollars.  However, this can be automatically converted to other currency units via the pull-down menu. 

Plywood and OSB Price Survey Information

The following is web survey of 4x8 sheets of plywood and OSB.  It provides the date of the web survey, the store and several price points on items that were advertised on the store's website.  This is for convenience only.  Local pricing should ALWAYS be used!

• Survey Date: 4/26/24
• Survey Store: Menards
  • Price of 4x8 3/4" Plywood: $35.55 USD
  • Price of 4x8 5/8" Plywood: $30.78 USD
  • Price of 4x8 1/2" Plywood: $28.95 USD
  • Price of 4x8 3/8" Plywood: $24.03 USD
  • Price of 4x8 3/4" OSB: $30.49 USD
  • Price of 4x8 5/8" OSB: $23.87 USD
  • Price of 4x8 1/2" OSB: $22.45 USD
  • Price of 4x8 1/4" OSB: $18.98 USD
  • Price of 4x8 3/4" Pressure Treated Plywood: $50.98 USD
  • Price of 4x8 1/2" Pressure Treated Plywood: $44.84 USD
  • Price of 4x8 5/8" Grooved Panel Siding: $53.39 USD
  • Price of 4x8 1/2" Grooved Panel Siding: $48.99 USD

NOTE 2: Some stores carry plywood and OSB with thicknesses 1/32^nd smaller than others.  Therefore, 3/4" might be represented by 23/32", 5/8" by 19/32", 1/2" by 15/32", and 3/8" by 11/32".

CAUTION: The pricing information provided is for calculating convenience with NO implied guarantees to the accuracy of the values listed. Authoritative sources should be sought to confirm any value before risking health or wealth on the veracity of the data. Furthermore, Calc gives no guarantee that you will be able to buy products at listed prices or even if they will be available.  The data provided is purely a convenience for making estimates, so we strongly recommend that one ALWAYS use local pricing and authoritative specifications.

The Pricing Data can be used for the Subflooring Material Cost Calculator, CLICK HERE or in the Cost of Plywood Calculator,CLICK HERE.

Deck Builder Calculator provides estimates for a simple rectangular deck project.  Calculator functions include the following:

• Deck Board Count: Computes the number of decking boards needed for your deck based on the size of the deck and the size of the decking boards.
• Deck Boards Cost: Computes the cost of deck board flooring based on a computed number of deck boards and the price per board.
• Decking Cost Estimate: Estimates the cost of wood board decking based on total area and unit pricing in dollars per square feet.
• Subfloor 4x8 Sheets: Computes the number of 4x8 sheets to cover floor/deck area.
• Subfloor Cost: Computes the cost of 4x8 sheets to cover fool/deck area.
• Deck Joist Count: Computes the number of floor joists needed for a deck.  It returns the number of joists and plate boards, square feet of area and the length of the diagonal.
• Joists on Beams: Computes the number of joists (2x dimensional lumber or i-joists), number of beams, number of joist hangers, and length of plate boards needed for a floor or deck with a span that might require one or more beams.
• Deck Joist Cost: Computes the total cost of the floor joist boards.
• Deck Stain and Sealer: Computes the amount of stain and sealer needed for a deck.

Room Floor Area Calculators

• Area of Room's Floor - Area of Floor in Rectangular Room
• Area of Room's Floor with Angled Bump-out - Area of Floor in Rectangular Room with Angled Bump-out
• Area of Room's Floor with Squared Bump-out - Area of Floor in Rectangular Room with Squared Bump-out

Most rooms are  simple rectangles with a length and a width.  The only common departure are rooms with bump-outs.  Some bump-outs are angular and taper down from an opening.  Some bump-outs have squared corners.  To compute the square feet of these floors are simple geometry based on the measurements of the main floor and the bump-out dimensions.

To compute the area of a floor with a different shape (e.g., circular, oval, or polygon), see the Area Calculator.