Construction & Building Calculators
Plan any building project with our free construction calculators. Whether you are pouring a concrete slab, laying bricks or blocks, sizing rebar, digging foundations or framing a structure, these tools give you accurate material quantities in seconds.
Every calculator supports both metric and imperial units and lets you add a waste allowance so you order the right amount first time. Pick the calculator that matches your task below.
Construction Calculators(30)
Concrete Calculator
Calculate how much concrete you need for slabs, footings, columns and walls in cubic yards or metres.
Concrete Mix Calculator
Work out the cement, sand and aggregate (ballast) quantities for a concrete mix by volume and ratio.
Concrete Footing Calculator
Calculate the concrete volume and number of bags needed for strip, pad and pier footings.
Concrete Cost Calculator
Estimate the total cost of concrete for a slab, footing or footpath from the volume and your price per cubic yard or metre.
Cement Calculator
Calculate the number of cement bags, sand and aggregate needed for a concrete or mortar mix by ratio.
Brick Calculator
This brick calculator works out how many bricks and how much mortar you need for any wall. Enter the wall size, deduct openings and choose your brick size to get an instant brick and mortar estimate using standard UK brick dimensions.
Mortar Calculator
Estimate mortar volume and cement, lime, sand quantities for bricklaying and blockwork.
Concrete Block / CMU Calculator
Calculate the number of concrete blocks or CMUs needed for a wall plus mortar requirements.
Rebar Calculator
Calculate the number of rebar pieces, total length, and weight for slabs, footings, and walls.
Foundation Calculator
Calculate concrete, rebar, and formwork needed for strip, pad, or raft foundations.
Post Hole Calculator
Calculate concrete and gravel needed for setting fence or deck posts in the ground.
Excavation Calculator
Calculate the volume of soil to excavate and the number of skip loads or truck loads needed.
Lumber / Timber Calculator
Calculate board feet, linear feet, and total lumber or timber needed for framing and woodworking projects.
Plywood / OSB Sheet Calculator
Calculate how many sheets of plywood or OSB you need to cover a floor, wall or roof area, including a waste allowance.
Beam / Load Calculator
A beam span and load calculator that works out the maximum span, beam size and load-bearing capacity for structural beams.
Joist Calculator
Calculate the number of joists, hangers, and blocking needed for floors and ceilings.
Joist Span Calculator
Find the maximum allowable span for floor and ceiling joists from the joist size, spacing and timber grade.
Stud Spacing Calculator
This stud spacing calculator (also a handy stud calculator and wall framing calculator) works out how many studs, top and bottom plates and framing timber you need at 400 or 600 mm centres for any partition or load-bearing wall.
Timber Fastener Spacing Calculator
This timber fastener spacing calculator works out how many nails, screws or bolts you need — and the correct spacing — for any timber connection. It doubles as a timber screw spacing calculator and a general timber connection calculator for decking, framing and structural joints.
Decking Screw Calculator – How Many Decking Screws Do I Need?
Work out how many decking screws you need and how far apart to space them, based on your deck size, board width and joist centres.
Staircase / Stair Calculator
Calculate rise, run, number of steps, stringer length, and headroom for any staircase.
Stair Stringer Calculator
Calculate stair stringer length, the number of notches and the rise and run cut marks for laying out a stringer board.
Roof Truss Calculator
Work out the number of roof trusses and the truss height for a roof from its length, span, pitch and truss spacing.
Reinforcing Mesh Calculator
Work out how many sheets of steel reinforcing mesh (A142, A193, A252, A393) you need for a slab, allowing for overlaps.
Block Fill Calculator
Estimate the concrete or grout needed to fill the cores of concrete blocks (CMU) for a wall, in bags or cubic metres.
Concrete Steps Calculator
Calculate the volume of concrete and number of bags needed to pour a flight of concrete steps from the rise, run and width.
Concrete Weight Calculator
Estimate the weight of a concrete slab, footing or volume from its dimensions, using standard concrete density.
Lumber Weight Calculator
Estimate the weight of timber and lumber from its dimensions and species, for softwood, hardwood and green timber.
Baluster Spacing Calculator
Work out evenly spaced balusters or spindles for a railing while keeping gaps within the 100mm (4in) safety limit.
Squaring Calculator
Check whether a layout is square using the 3-4-5 method and diagonal measurements for foundations, decks and walls.