Construction
Material quantity calculators using standard densities and coverage rates, with sensible waste margins.
Concrete Calculator
Calculate the concrete volume, number of bags and weight needed for a slab, footing or pad from length, width, depth and bag yield.
Brick Calculator
Calculate how many bricks, blocks and mortar bags you need for a wall from its length, height, brick type and waste allowance.
Gravel Calculator
Calculate how many tonnes of gravel or aggregate you need for a driveway or path from area, depth and bulk density.
Asphalt Calculator
Calculate the tonnes of hot-mix asphalt needed for a driveway or path from area, thickness and material density.
Mulch Calculator
Calculate how much mulch you need for a garden bed in cubic meters, liters, cubic yards and 50L bags from area and depth.
Board Foot Calculator
Calculate board feet from a board's nominal thickness, width and length, plus total cost — the standard US unit for pricing hardwood and dimensional lumber.
Cubic Yard Calculator
Convert length, width and depth into cubic yards, cubic feet and cubic meters for concrete, gravel, soil or mulch orders, with a 10% waste allowance.
Lumber Calculator
Calculate total lumber length and cost from piece count, length per piece and price per meter, with an adjustable waste allowance for cuts and offcuts.
Wall Area Calculator
Calculate gross and net wall area from perimeter and height, subtracting standard door and window openings, for paint, drywall or siding estimates.
Square Yard Calculator
Convert a length and width in feet into square yards, square feet and square meters. Standard divide-by-9 conversion used for carpet and flooring.
Gallons per Square Foot Calculator
Estimate gallons of paint, sealer or coating from area, coverage rate (sq ft per gallon) and number of coats. Includes liters and gal/ft².
Roof Pitch Calculator
Convert roof rise and run into pitch (X-in-12), angle in degrees, slope percentage and the rafter length multiplier.
Roof Area Calculator
Calculate true sloped roof area from building footprint and pitch, plus square feet, roofing squares and a waste allowance.
Shingle Calculator
Calculate asphalt shingle bundles and roofing nails needed from roof area and a waste allowance, using standard trade conventions.
Rafter Length Calculator
Calculate common rafter length from run and pitch (or rise), including the overhang converted to its along-the-slope length.
Metal Roofing Calculator
Calculate metal roofing panels and screws needed from roof area, panel coverage width and length, with an optional cost estimate.
Roof Snow Load Calculator
Estimate flat and sloped roof snow load from ground snow load, exposure, thermal condition and roof pitch, using the ASCE 7 flat-roof form.
Birdsmouth Cut Calculator
Calculate the heel depth of a rafter's birdsmouth cut from roof pitch and seat width, and check it against the remaining rafter depth.
Gambrel Roof Calculator
Size a classic gambrel (barn) roof with the circle method: equal rafter lengths, peak height, roof area and the 60°/30° slope pair from the building span.
Stud Wall Calculator
Estimate the studs and plates needed to frame a wall from its length, stud spacing (400/600mm) and number of openings.
Drywall Calculator
Calculate drywall sheets, screws, joint compound and tape needed from area, sheet size and a waste allowance.
Insulation Calculator
Calculate the insulation thickness needed to reach a target R-value for fiberglass batt, cellulose, spray foam or rigid foam.
Stair Calculator
Calculate stair risers, tread depth, total run and stringer length from total rise, using Blondel's rule and comfort guidance.
Wallpaper Calculator
Calculate wallpaper rolls needed from wall width and height, roll dimensions and pattern repeat.
Paver Calculator
Calculate pavers, jointing sand and bedding sand needed from area, paver size, joint gap and a waste allowance.
Fence Calculator
Calculate fence posts, rails, pickets and post-hole concrete needed from fence length, spacing and picket dimensions.
Decking Calculator
Calculate deck board rows, total linear board length and screws needed from deck size, board width, gap and waste allowance.
Plywood Calculator
Calculate how many plywood sheets you need to cover an area, based on standard sheet sizes and a waste allowance.
Floor Joist Calculator
Calculate the number of floor joists needed and total linear length from wall length, on-center spacing and joist span.
Beam Span Calculator
Estimate a beam's tributary line load, end reaction and maximum bending moment from span, joist spacing and floor load.
Beam Load Calculator
Calculate end reaction, maximum bending moment, maximum shear and total load for a simply supported beam under a uniform load.
Beam Deflection Calculator
Estimate a simply supported beam's midspan deflection under a uniform load and compare it against the common L/360 serviceability limit.
Door Header Calculator
Estimate a residential door or window header depth from opening width and wall bearing condition, using a rule-of-thumb framing guide.
Roof Truss Calculator
Calculate the number of roof trusses needed, top and bottom chord lengths, and peak height from building length, span, pitch and spacing.
Baluster Spacing Calculator
Work out how many balusters a railing span needs and the even gap between them, using the 4-inch sphere rule from the IRC/IBC guard provisions.
Miter Angle Calculator
Find the miter cut angle for any corner or multi-sided frame: corner angle ÷ 2 for two pieces, (180 − 360/n) ÷ 2 for n-sided frames, plus the saw setting.
BTU Calculator
Estimate rough heating/cooling output in watts and BTU/h from room volume and insulation quality, for planning purposes.
AC Tonnage Calculator
Convert a cooling load in BTU/h (or a rough area estimate) into air-conditioning tonnage and kilowatts.
Air Changes Calculator
Calculate air changes per hour (ACH) from airflow and room volume, or the airflow needed to reach a target ACH.
Cement Calculator
Calculate cement bags, sand and aggregate volume for a nominal concrete mix ratio (1:2:4, 1:1.5:3 or 1:3:6) using the standard 1.54 dry-volume factor.
Concrete Mix Ratio Calculator
Enter any custom cement, sand and aggregate ratio and a target wet volume to get ingredient volumes and an estimated water quantity.
Rebar Calculator
Estimate the number of reinforcing bars and total rebar length for a slab grid from slab dimensions, spacing and edge clearance.
Concrete Block Fill Calculator
Estimate the grout volume and number of 80 lb bags needed to fill the cores of concrete masonry (CMU) blocks, by block size.
Concrete Column Calculator
Calculate concrete volume, weight and 20 kg bag count for round or rectangular columns from diameter or width, depth/side and height.
Sonotube Calculator
Calculate concrete volume and 80 lb or 60 lb bag counts for cylindrical Sonotube footings from diameter, height and quantity.
Post Hole Concrete Calculator
Calculate concrete volume and 20 kg bag count for fence or deck post holes, accounting for the post's own volume displacing concrete.
Concrete Stair Calculator
Calculate concrete volume for solid-on-grade stairs from step count, rise, run and width, plus the 20 kg bag count needed.
Mortar Calculator
Estimate mortar bags and site-mix sand volume needed per 1,000 bricks or per concrete block, based on standard 3/8 inch joint conventions.
Grout Calculator
Calculate grout weight needed for a tiled area from tile size, thickness and joint width, using the standard industry grout-weight formula.
Thinset Calculator
Estimate 50 lb thinset mortar bags needed for a tiled area based on trowel notch size, using published coverage figures.
Concrete Driveway Cost Calculator
Estimate concrete volume and total cost for a driveway from length, width, thickness and a price per cubic meter, with a waste allowance.
Concrete Weight Calculator
Convert a concrete volume into weight in tonnes, kilograms and pounds using published typical densities for normal, reinforced and lightweight concrete.
Concrete Slab Cost Calculator
Estimate the ready-mix cost of a concrete slab from its dimensions, thickness, price per cubic meter and a waste allowance. Reports order volume and area.
Concrete Footing Calculator
Calculate the concrete volume of a strip footing from its length, width and depth, with a 10% waste allowance and the approximate weight in tonnes.
Sand Calculator
Calculate the volume, weight and number of 25 kg bags of sand needed for a given area and depth, using a typical dry-sand density.
Aggregate Calculator
Calculate the volume and weight of crushed stone, gravel base, river rock or limestone needed for an area, by material-specific density.
Road Base Calculator
Calculate the loose gravel base volume to order for a target compacted depth, accounting for compaction shrinkage, plus estimated weight.
Retaining Wall Calculator
Calculate the number of retaining wall blocks, cap units, base gravel and drainage backfill needed from wall length, height and block size.
French Drain Calculator
Calculate the gravel volume and weight needed for a French drain trench, accounting for the volume displaced by the drain pipe.
Gravel Driveway Calculator
Estimate gravel tonnage for a two-layer driveway: compacted dense-grade base plus surface gravel. Reports tonnes per layer, total volume and area.
Elevation Grade Calculator
Convert rise and run into grade percentage, slope angle in degrees, a 1:n ratio and the slope length. Standard rise-over-run conversions.
Fence Post Depth Calculator
Calculate how deep to bury a fence post and the recommended hole diameter from post height and width, using standard fencing conventions.
Paver Sand Calculator
Calculate the bedding sand volume, weight and number of bags needed under a paver installation from area and bed depth.
Siding Calculator
Calculate net siding area, area with waste allowance and siding squares needed from wall perimeter, height and opening area.
Deck Stain Calculator
Calculate how much deck stain you need in liters and cans from deck area, number of coats and the product's coverage rate.
Sealant Calculator
Calculate the volume of sealant or caulk needed and how many cartridges to buy from joint length, bead width and bead depth.
Ramp Calculator
Calculate ramp run length, surface length and angle from rise and a chosen slope ratio, including the ADA 1:12 maximum slope.
Board and Batten Calculator
Work out how many battens a board-and-batten wall needs from wall length, height and on-center spacing, plus linear meters and board area with 10% waste.
Wainscoting Calculator
Estimate wainscoting panels, chair rail length and panel area from room perimeter, height, panel width and the number of door and window openings.
Pipe Volume Calculator
Calculate the internal volume of a pipe in liters and US gallons from its inner diameter and length, using the cylinder volume formula.
Water Tank Calculator
Calculate the volume, weight and fill level of a cylindrical or rectangular water tank in liters, cubic meters and US gallons.
Pool Volume Calculator
Calculate swimming pool water volume in liters, US gallons and cubic meters from pool shape, dimensions and shallow/deep-end depths.
Pond Volume Calculator
Estimate garden pond volume in liters and US gallons from length, width and average depth, using the ~80% rule for irregular informal pond shapes.
Pond Liner Calculator
Work out the flexible pond liner sheet size from pond length, width, maximum depth and edge overlap, using the standard dimension + 2×depth + 2×overlap rule.
Pipe Flow Rate Calculator
Calculate volumetric flow through a pipe from inner diameter and flow velocity using the continuity equation Q = v × A. Results in L/s, m³/h and US gpm.
Rolling Offset Calculator
Calculate pipefitting rolling offsets: true offset from roll and offset, then travel and run for 45°, 30° or 60° fittings using the standard trade formulas.