Construction Calculators
Estimating and layout tools for concrete, masonry, framing and site work. Every calculator states its yield data, density assumptions and code references, separates the geometric result from the ordering figure, and flags where the rule of thumb stops applying.
Concrete & Masonry
Volume, mix proportions, block and brick counts, and reinforcement takeoffs.
- Concrete CalculatorCalculate concrete volume in cubic yards and bags for slabs, footings, walls and columns. Includes 80/60/40 lb bag counts, 5% waste allowance and weight for delivery.
- Concrete Mix Ratio CalculatorCalculate cement bags, sand, gravel and water for any mix ratio (1:2:3, 1:1.5:3, 1:3:4) and target volume. Uses the 1.54 dry-volume factor and w/c 0.5.
- CMU Block CalculatorCalculate concrete blocks (CMU) for any wall: 4, 6, 8, 12 inch block counts, mortar bags, sand and wall weight. Nominal dimensions with 5% breakage included.
- Brick CalculatorCalculate bricks for any wall: US modular and UK standard bricks, stretcher/English/Flemish bonds, mortar bags. Counts include joints and 5% waste.
- Rebar Grid CalculatorCalculate rebar for slabs: bar count both directions, total length with lap splices, weight by bar size (#3–#8), and ACI shrinkage minimum check with spacing chart.
Structural Layout
Footing sizing, wall framing, stairs and roof geometry — the load-bearing layout tools.
- Footing Size CalculatorSize a spread footing from column load and allowable soil bearing pressure. Square, rectangular or circular footings with practical 0.5 ft snapping and utilization check.
- Stud Wall CalculatorCalculate studs, plates and board feet for framed walls: 16 or 24 in OC layout, openings allowance, cut stud length, sheathing sheets. Includes 3-plate framing.
- Stair CalculatorCalculate stair layout: number of risers, actual riser height, tread count, total run, stringer length and the 2r+t comfort rule — with IRC 7¾ in and 10 in compliance checks.
- Roof Pitch CalculatorConvert roof pitch to angle, percent slope and the area multiplier. Enter the rise per 12 and footprint area to get the actual sloped roof area and rafter factor.
Materials & Estimating
Lumber volume, aggregates, board and paving quantities for material orders.
- Board Foot CalculatorCalculate board feet for lumber: thickness in quarter-inches (4/4, 5/4, 6/4), width, length and piece count, with total cost at any price per board foot.
- Gravel CalculatorCalculate gravel, sand, crushed stone, topsoil or mulch: cubic yards, tonnage by material density, bags for small jobs, with a 10% margin for uneven subgrade.
- Drywall CalculatorCalculate drywall sheets (4×8, 4×10, 4×12), joint compound, tape and screws for any room — walls and optional ceiling, with the standard 15% waste allowance.
- Asphalt CalculatorCalculate hot mix asphalt tonnage for driveways and parking areas: compacted tons, loose order quantity with 25% compaction allowance, square yards and cost estimate.
Design guide
How these calculations fit together in real projects — the order to run them in, and the decisions each one answers.