Construction Calculators
Asphalt Calculator
Convert paved driveway or lot area and depth in inches into tons of hot-mix asphalt using the standard compacted density assumption paving crews rely on.
Brick Calculator
Count the bricks a wall needs by factoring in mortar joint thickness and door or window openings, for standard modular brick or custom brick dimensions.
Cement Bags Calculator
Convert a finished concrete volume and a cement to sand to aggregate mix ratio into the exact number of cement bags, accounting for dry-mix shrinkage.
Concrete Blocks Calculator
Count the concrete masonry blocks a wall needs after subtracting door and window openings, based on standard 16x8 in or custom block face area dimensions.
Concrete Calculator
Work out concrete volume in cubic yards for rectangular slabs, footings, or cylindrical columns, plus how many 60 lb or 80 lb bags a small pour needs.
Construction Cost Calculator
Estimate total project cost from area and cost per square foot, with an adjustable contingency percentage for overruns plus separate permit fees added.
Deck Material Calculator
Work out decking board count and joist count separately from deck length, width, board face width, purchasable board length, and joist spacing on-center.
Dry Concrete Volume Calculator
Convert a finished wet concrete volume into the dry cement, sand, and aggregate volume needed before mixing, using the standard 1.54 shrinkage factor.
Drywall Calculator
Work out the number of standard 4x8 drywall sheets a wall or ceiling area needs from total square footage, including an adjustable cut and waste allowance.
Fence Calculator
Work out post, panel, and rail counts for a fence run from its total length, the post spacing on-center, and the number of rails per section needed to build it.
Flooring Calculator
Convert room length and width into total flooring material needed for laminate, vinyl, or hardwood, with an adjustable waste allowance and box-count conversion.
Footing Calculator
Calculate the concrete volume needed for a continuous strip footing from its width, depth in inches, and the total wall length it runs beneath the wall.
Foundation Calculator
Work out the concrete volume a foundation slab needs in cubic yards from its length, width, and pour depth, including a standard waste allowance amount.
Gravel Calculator
Convert driveway, pathway, or drainage bed length, width, and depth into cubic yards and delivery weight in tons using standard compacted gravel density.
Heat Exchanger Calculator
Calculate sensible heat duty in kilowatts or Btu per hour from a fluid stream's mass flow rate, specific heat, and temperature change across the exchanger.
I-Beam Calculator
Work out an I-beam's total weight from its flange width, flange thickness, web height, and web thickness by finding its true cross-sectional area first.
Insulation Calculator
Convert wall, attic, or floor area into the number of insulation packages needed based on each package's stated coverage and an adjustable waste allowance.
Lighting Calculator
Apply the lumen method to work out how many light fixtures a room needs from its area, target light level, fixture output, and a chosen light loss factor.
Lumber Calculator
Convert board thickness, width, length, and quantity of boards into total board feet, the actual unit lumber yards use to price dimensional lumber stock.
Mulch Calculator
Convert garden bed area and mulch depth in inches into cubic yards and standard 2 cubic foot bag counts for effective, weed-suppressing bed coverage depth.
Paint Calculator
Turn wall length, height, door count, window count, and number of coats into the exact number of paint gallons a room needs, including a waste overage.
Patio Calculator
Switch between paver counts and concrete slab volume for a patio project, including sand base depth, cut waste allowance, and bagged concrete estimates.
Plywood Calculator
Convert a floor, wall, or roof area into the number of standard 4x8 plywood sheets needed, including an adjustable cutting and trim waste allowance figure.
Rebar Calculator
Work out the two-way rebar grid a slab needs, including bar count in each direction, total linear length, and total steel weight by bar size selected.
Retaining Wall Calculator
Work out the concrete volume a poured retaining wall needs from its length, height, and thickness, using a tighter formwork-based waste margin default.
Roofing Calculator
Convert a roof's flat footprint into its true sloped surface area using the roof pitch, then into standard roofing squares and shingle bundle counts needed.
Siding Calculator
Work out the net siding area and trade-standard squares needed for a wall after subtracting door and window openings and adding a cutting waste allowance.
Sod Calculator
Convert lawn length and width into the number of sod rolls needed to order, based on your supplier's roll size and an adjustable waste allowance for edges.
Stair Calculator
Solve for the number of steps, the actual riser height, and the stringer length from a staircase's total rise, target riser height, and tread depth entered.
Steel Weight Calculator
Calculate the weight of a steel rectangular bar, plate, or hollow pipe from its dimensions using standard steel density for accurate order weight totals.
Structural Beam Calculator
Calculate maximum deflection at the center of a simply-supported beam under a uniform load from its span, load, modulus of elasticity, and moment of inertia.
Tile Calculator
Work out exactly how many tiles a room needs from the room dimensions and tile size in inches, with an adjustable waste allowance for cuts and breakage.
Measuring Twice Before You Buy Materials
Construction material estimates protect against both expensive shortfalls and wasteful overordering — getting concrete, lumber, or roofing quantities right the first time saves real money on every project. These calculators cover the takeoff math for the most common building materials.
Worked Example: Concrete for a Slab
- Measure the slab: 20 feet by 20 feet, poured 4 inches thick.
- Convert thickness to feet: 4 ÷ 12 = 0.333 feet.
- Multiply: 20 × 20 × 0.333 = 133.3 cubic feet.
- Convert to cubic yards (divide by 27): 133.3 ÷ 27 = 4.94 cubic yards.
- Round up for ordering: 5 cubic yards, allowing for minor spillage and uneven subgrade.
The Concrete Calculator runs this exact conversion for any slab or footing dimensions — underordering even slightly means a costly second truck delivery mid-pour.
Pro tip: many contractors add 5-10% on top of the raw calculated quantity for cuts and offcuts across most materials — check your specific project's layout complexity before ordering exactly to the calculated number.
Popular Construction Calculators
- Lumber Calculator — totals board feet needed for a framing or decking project.
- Roofing Calculator — estimates shingle or material quantity from roof area and pitch.
- Drywall Calculator — calculates the number of sheets needed to cover a given wall and ceiling area.
- Rebar Calculator — totals reinforcement bar length and quantity for a given slab or footing layout.
Related: Civil Engineering Calculators for structural design, Home Improvement Calculators for smaller upgrade projects.