Construction & Building Calculators — United Kingdom

Work out how much concrete a slab, path or footing needs — in cubic metres or yards, with a waste allowance, the number of bags and the weight.

Work out how much gravel, crushed rock, sand, road base, topsoil or mulch an area needs, in cubic metres or yards and in tonnes.

Count the bricks a wall needs from its area and the brick size, with a waste allowance and the mortar volume.

Work out the concrete needed to set fence or deck posts: the volume per hole after the post is in, the total, and the number of bags.

How many concrete blocks a wall needs, plus the mortar, and the cost — from the wall size and the block you are using.

How much grout or concrete it takes to fill the cores of a block wall — for reinforced or partially filled blockwork.

The concrete needed for round or rectangular columns and piers — per column and for the whole set, in bags or by volume.

Concrete for cylindrical form tubes — deck footings, posts and piers — per tube and for the whole job.

The weight of concrete from its volume or slab dimensions — for transport limits, floor loading and skip capacity.

The concrete volume for a flight of stairs — the steps plus the waist slab beneath — with the step geometry checked against the usual rule.

The volume of an excavation and the spoil it produces — for round or rectangular holes, trenches and pits.

How much a pipe holds, what that weighs in water, and how long it takes to fill or flush at a given flow rate.

The water volume of a round pool — with the chlorine dose, fill time and the weight it puts on the ground.

The capacity of a tank — vertical or horizontal cylinder, or rectangular — with the partial volume at a given fill level.

The weight of a length of pipe — the material itself and its contents — for lifting, supporting and transport.

Work out how much paint a room needs from the wall perimeter and height, less doors and windows, for the number of coats — in litres or gallons and tins.

Count the tiles a floor or wall needs from the area, tile size and grout gap, with a cutting allowance and the number of boxes.

Work out how many boxes of laminate, engineered timber or vinyl planks a room needs from its dimensions, the box coverage and a waste allowance.

Count the plasterboard (drywall) sheets a wall or ceiling needs from its area and the sheet size, with a waste allowance and the screws.

Work out how many rolls of wallpaper a room needs from the perimeter, wall height, roll size and pattern repeat.

Work out how much carpet to buy from the roll for a room — the linear length, the area bought and the waste — from the room size and roll width.

Convert a roof's rise and run into pitch in degrees and as a ratio, and get the rafter length and roof slope factor.

Count the decking boards a deck needs from its size, the board width and gap, and the board length — with the linear length and screw count.

Count the posts, rails and pickets a fence run needs from its length, post spacing, rails per section and picket size.

Work out how many packs of insulation batts or rolls a ceiling, wall or floor needs from its area and the coverage per pack.

Timber quantity and cost — board feet, cubic metres, linear length and price — from the section size and the number of pieces.

The weight of a timber order — by species and moisture content — for transport limits, lifting and structural dead load.

The studs, plates and noggings a stud wall needs — from its length, height and stud spacing.

The length of a common rafter from the span and roof pitch — with the overhang, plumb cut angle and total timber.

How deep a fence post should go and how much concrete the hole needs — using the one-third rule and the hole size.

How many pickets, rails and posts a fence needs — for butted or spaced palings — with the exact gap to make it come out even.

The load snow puts on a roof — from depth and snow type — with the total weight and how the roof pitch reduces it.

How many balusters a run of railing needs so that no gap exceeds the maximum allowed — from the run length, the baluster width and the gap limit — with the actual gap, the centre-to-centre spacing, and the layout from the first post.

The board feet in a piece or a stack of lumber from its thickness, width and length — the unit hardwood is sold by — with the total for a quantity, the cost at a price per board foot, and the equivalent in cubic metres.

The torque that gives a bolt its intended clamping force — from the thread size and pitch, the property grade's proof stress, the share of proof load to preload to, and the nut factor for the lubrication — with the preload, the tensile stress area and the torque in both units.

A first-pass size for the timber header or lintel over a door or window — the beam depth that bending strength and deflection each demand for the span and the load on it — with the next standard depth and how much of its capacity the load uses.

Work out the number of steps, the exact riser height, the total run and the stringer length for a staircase from its total rise, and check the comfort rule.

Convert a ramp's rise and run into a gradient ratio (1 in x), a percentage and an angle, and check it against the common accessibility limits.

Add up the floor area of up to four rectangular rooms or sections, in square metres, square feet and square yards.

Count the pavers a patio, path or driveway needs from the area and paver size, with a cutting allowance and the bedding sand.

Floor area ratio, site coverage and how much floor area a site allows — the planning numbers that decide what can be built.

The heat that flows through a window or door — from its area, its U-value and the temperature difference across it — in watts and over a heating season, with the energy cost and what upgrading to a lower U-value would save.

The voltage lost along a cable — from its length, the conductor size, the current and the material — as volts and as a share of the supply, with the power wasted as heat, whether it sits inside the usual limit, and the conductor size that would.

How much topsoil an area needs at a given depth — the volume, the weight at a bulk density, the number of bags, and the cost with a wastage allowance — in metric or imperial units.

The weight of a metal plate or sheet from its length, width and thickness — for steel, stainless, aluminium, copper and brass — with the weight per unit area, the total for a quantity, and the cost at a price per kilogram.

How much asphalt a paving job needs — the compacted volume, the tonnes at a compacted density, a wastage allowance, and the cost at a price per tonne — for a driveway, car park or road patch.

The positions of equally spaced holes on a bolt circle — the angle of each, the straight-line distance between neighbours, and the x–y coordinates from the centre — from the pitch circle diameter, the number of holes and the angle of the first.

The materials for a French drain — the gravel in cubic metres and tonnes after the pipe's volume is taken out, the perforated pipe, the filter fabric to line the trench, and the spoil to remove — from the trench length, width and depth.

A first estimate of the heating output a home needs — from its floor area, the climate's heating factor, the ceiling height and the insulation standard — in kilowatts and BTU per hour, with a margin, and the furnace or heat-pump size to look for.