Free Construction Calculators — Built for the Field

11 trade-specific estimating tools built on IRC codes and manufacturer specs. Material quantities and insurance costs in seconds — no account, no cost.

All Calculators

  • Roofing Calculator — Calculate shingles, underlayment, and ridge cap for gable roofs. Enter building dimensions and roof pitch — waste factor included.
  • Wall Framing Calculator — Estimate studs, top plates, bottom plates, and headers for any wall layout. Supports 16" and 24" on-center spacing per IRC requirements.
  • Concrete Slab Calculator — Compute cubic yards of concrete for slabs, walkways, driveways, and patios. Accounts for slab thickness and optional waste overage.
  • Footings Calculator — Determine concrete volume for strip footings, pier footings, and pad footings. Sized to IRC minimum bearing requirements by soil class.
  • Drywall Calculator — Estimate sheets of drywall, joint compound, tape, and screws for walls and ceilings. Subtract openings for doors and windows automatically.
  • Paint Calculator — Find how many gallons you need to cover walls, ceilings, or trim. Supports single and double coat calculations with spread rate adjustment.
  • Flooring Calculator — Calculate square footage of hardwood, LVP, tile, or carpet with waste factor built in. Works for simple rectangles or L-shaped rooms.
  • Board Feet Calculator — Convert lumber dimensions into board feet for accurate purchasing and pricing. Supports multiple board sizes and quantity inputs.
  • Stair Calculator — Design code-compliant stairs with correct riser height, tread depth, and stringer length per IRC Section R311. Outputs cut dimensions.
  • Insulation Calculator — Determine batts or bags of blown insulation needed to hit your target R-value for walls, attics, and floors. Based on DOE climate zone recommendations.
  • Builder's Insurance Estimator — Estimate Builder's Risk and General Liability insurance costs for your construction project. See coverage minimums and what to ask your agent.

Every calculator uses formulas drawn from the International Residential Code (IRC) and standard manufacturer specifications. Outputs are estimates intended to support material orders and supplier quotes; always verify with your local building department and structural engineer.