Subfloor & Underlayment Calculator
Estimate 4x8 plywood or OSB subfloor sheets, tongue-and-groove waste buffer, screws, and construction adhesive tubes.
Input Parameters
Enter dimensions and specifications to estimate materials.
4x8 Subfloor Sheets Needed
Total Floor Area
280sq ft
Subfloor Screws
360screws
28oz Adhesive Tubes
5tubes
Specified Thickness
3/4"
Material estimates include recommended trade waste buffer. Always confirm dimensions on site prior to ordering.
How The Calculation Works
Formulas, material coverage assumptions, waste buffers, and rounding standards.
Standard subfloor panels measure 4ft × 8ft (32 sq ft).
Staggered tongue-and-groove layout requires trimming at perimeter walls, warranting an 8-10% cut allowance.
Screws are calculated at 6" spacing along perimeter edges and 12" on intermediate joists (approx 36 screws per panel).
You May Also Need
Common complementary tools used alongside this calculator for complete project estimation.
Tile Installation Cost & Material Calculator
Calculate square footage, exact tile counts, waste buffers, material cost per square foot, and box quantities for straight, diagonal, or herringbone layouts.
Flooring Cost Calculator
Estimate square footage, box requirements, waste factors, and total material costs for hardwood, laminate, vinyl plank, and tile.
Grout Calculator
Calculate pounds or kilograms of sanded, unsanded, or epoxy grout needed based on tile dimensions, joint width, and depth.
Carpet & Padding Calculator
Calculate square yards, square meters, roll lengths, tack strips, and padding for 12ft and 15ft carpet rolls.
Tile Mortar & Thinset Calculator
Estimate 50lb bags of thinset mortar based on square footage and trowel notch size (1/4", 3/8", 1/2" or V-notch).
Baseboard & Trim Calculator
Calculate linear feet, board quantities (8ft, 12ft, 16ft), finish nails, and caulk for perimeter baseboard trim.
Frequently Asked Questions
Practical installation guidance and purchasing tips for subfloor & underlayment calculator.