All Construction Calculators

How many anchor bolts do I need? Free calculator for J-bolt & wedge types at standard 1.8 m spacing — includes total count and layout tips.

Sill seal calculator: Estimate foam gasket rolls by foundation perimeter. Free tool for 90 mm & 140 mm widths — prevents air infiltration.

How much pressure treated timber for sill plates? Instant calculator for 100×50 mm & 150×50 mm PT boards — gives linear metres and board count.

How much concrete do I need? Free calculator for slabs, footings & columns — gives cubic metres and bag counts with waste factor.

How much concrete for a slab? Free calculator for garage, patio & driveway slabs — gives cubic metres and bag count for any thickness.

Concrete footing calculator: Estimate cubic metres for continuous & spread footings. Free tool for foundation walls — includes waste factor.

How much concrete for column piers? Free column calculator for 200 mm, 250 mm & 300 mm diameter piers — gives cubic metres per column and total.

Concrete steps calculator: How many cubic metres for stairs? Free tool — enter width, rise, run & step count for instant estimate.

How much gravel do I need? Free calculator for any area — cubic metres, tonnes, and cost estimate with 10% wastage factor.

Driveway gravel calculator: Estimate tonnes and cost by type — crushed stone, pea gravel, MOT Type 1, or decomposed granite with delivery.

Block fill calculator — how much concrete to fill concrete blocks? Free tool for 100 mm, 140 mm & 215 mm blocks. Get cubic metres and bag count instantly.

Mortar mix calculator — free tool to estimate bags of mortar for blockwork, brickwork & stone. Covers designations M2, M4 & M6 with joint thickness options.

Retaining wall calculator — free tool for block, masonry & stone walls. Get block count, coping stones, gravel backfill & drainage estimates instantly.

How much reinforcement bar do I need? Free calculator for slabs, footings & walls — gives bar count, linear metres, weight in kg, and 6 m bar total.

Reinforcement spacing calculator — free tool to find optimal grid layout by load type. Get bar count, linear metres, and chair supports for any slab.

Rim joist calculator: How many boards for your floor perimeter? Free tool for common timber sizes — includes board count and linear metres.

Free floor joist calculator — get joist count by span & spacing. Covers 400 mm and 600 mm centres with sizing charts and board totals.

How many rows of bridging do I need? Free calculator for timber cross-bridging & solid blocking by joist span — instant results.

Subfloor adhesive calculator: How many tubes of construction adhesive? Free estimator based on floor area — covers standard cartridge sizes.

How many OSB sheets do I need? Free UK calculator for 1200×2400 mm OSB/3 floor panels — instant sheet count, waste allowance, and 2026 prices.

How many studs do I need? Free wall stud calculator for 400 mm & 600 mm centres — includes extras for corners, doors, and window openings.

Bottom plate calculator: Estimate sole plates by wall length. Free tool that gives board count and total linear metres needed.

How much timber for double top plates? Free calculator — gives exact board count with overlap stagger included.

Header calculator: What size header for my opening? Free tool for door & window spans — covers common header sizes.

How many sheets of sheathing for exterior walls? Free calculator for OSB & plywood panels — includes waste factor estimates.

Free rake wall calculator — get stud count, individual heights, and cut angle for walls following the roof pitch.

Free roof truss calculator — get truss count & spacing for any roof length. Enter span for 600 mm centres layout, cost estimate & tips.

Free rafter calculator — get rafter length, count & spacing for any roof type. Covers 400 mm and 600 mm centres for gable & hip roofs.

Ridge board calculator UK: What size ridge board do I need? Free tool for C16/C24 softwood sizing — board count, length, and 2026 timber prices.

How many OSB sheets to sheathe my roof? Free roof decking calculator for 1200×2400 mm panels — factors in roof pitch and waste.

Free shingle calculator for roof shingles — get bundles, squares & cost from square metres. Covers standard & architectural shingles.

How many rolls of roofing underlayment? Free calculator for breathable membrane & felt — accounts for overlap and waste.

Drip edge calculator: Estimate linear metres of flashing for your roof. Free tool — gives piece count for standard drip edge strips.

What pitch is my roof? Free roof pitch calculator — enter rise & run for instant angle, slope %, and area multiplier.

Free roof area calculator — convert flat dimensions to true roof area using pitch multiplier. Get roofing squares & material estimates.

Roof slope calculator — free tool to find pitch, angle, and sloped roof area multiplier. Enter rise & run for instant results in metres and degrees.

Free hip roof calculator — get rafter count, hip rafter length, roof area & ridge length. Covers common, hip & jack rafters for any building size.

Free gambrel (barn) roof calculator — get upper & lower rafter counts, roof area & wall height gained. Enter two pitches for instant results.

Free gable roof calculator — get rafter count, ridge length, roof area & gable end area. Enter building dimensions and pitch for instant estimate.

Free lean-to (shed) roof calculator — get rafter count, rafter length, roof area & rise height. Single-slope calculator for extensions & sheds.

How many rolls of breather membrane do I need? Free calculator by wall area — covers standard roll widths with overlap.

Free vinyl siding calculator — enter wall area in square metres for exact panel count. Accounts for doors, windows & 10% waste factor.

How many HardiePlank boards do I need? Free fibre cement cladding calculator — with waste included.

Window flashing tape calculator: Estimate linear metres for all openings. Free tool for self-adhesive flashing tape.

How many soffit panels do I need? Free calculator by perimeter and eaves width — includes J-channel and ventilation.

Free board and batten calculator — get board and batten count by wall area. For vertical exterior cladding.

How many insulation batts do I need? Free calculator for mineral wool and PIR insulation — covers standard wall cavities.

How much plasterboard do I need? Free calculator for 12.5 mm & 15 mm sheets — estimates 1200×2400 mm boards for walls and ceilings.

Plasterboard screw calculator: How many screws per board? Free estimator — gives total count and boxes needed.

How much jointing compound do I need? Free calculator for plasterboard finishing — estimates buckets for taping, bedding & skim coats.

Framing nail calculator: How many kilograms of nails for my project? Free tool for standard framing nails — based on stud count.

How many joist hangers do I need? Free calculator for standard joist hanger connectors — covers floor and ceiling joist framing.

Truss clip calculator: Estimate rafter-to-wall connectors for wind resistance. Free tool for standard truss clips and straps.

How much does timber cost? Free calculator for common structural timber sizes — estimates total cost by quantity and current prices in £.

Board feet calculator — enter timber thickness, width & length for instant BF total. Free hardwood pricing tool with cost estimate in £ for any species.

Free plywood calculator — get exact sheet count & cost for any project. Covers 6 mm to 18 mm thickness in 1220×2440 mm panels with waste.

Paint calculator — free square metre estimator for walls & ceilings. Select coats, get instant litres, tin count, and coverage for your project.

Paint cost calculator: Estimate total project cost by quality level. Free tool for trade to premium — includes supplies estimate in £.

How much primer do I need? Free calculator for new plasterboard, timber & repaints — adjusts coverage by surface type.

Epoxy calculator — how much epoxy for your garage floor? Free tool for any area. Get litres, kits & cost estimate for 1-coat and 2-coat systems.

How many deck boards do I need? Free calculator for treated, cedar & composite boards — gives board count, linear metres, and waste factor.

Deck footing calculator: How many concrete piers for my deck? Free tool — gives footing count, post layout, and beam spacing.

How many railing posts and balusters do I need? Free deck railing calculator — gives post count, baluster total, and rail linear metres.

Deck stair calculator: How many steps and stringers? Free tool — enter deck height for step count, stringer quantity, and tread boards.

Post hole calculator — how much concrete for fence posts? Free tool for any hole size. Get exact bag count for 25 kg & 40 kg postcrete bags.

Pond calculator — free tool for volume, liner size & pump capacity. Enter dimensions for rectangular, oval or kidney-shaped ponds instantly.

Fence calculator — how many posts, rails & pales for your fence? Free fence material calculator for timber fences. Get a complete material list instantly.

Fence post calculator — how many posts and bags of postcrete? Free tool gives post count, concrete bags & gravel for any fence length.

Fence panel calculator — how many pre-made panels for your fence? Free tool for 6 ft & 5 ft panels. Get panel count, posts & post caps.

Picket fence calculator — how many pickets with custom spacing? Free tool for any picket width & gap. Get picket count, rails, posts & total board metres.

Free deck board spacing calculator — get even gaps between boards for any board width and deck length. Prevents buckling and water pooling.

Flooring calculator — free square metre estimator for any room. Get box count, waste factor & material list for hardwood, LVP, and engineered wood.

Carpet calculator — free tool to estimate square metres, linear metres & underlay needed. Works for 4 m and 5 m wide rolls with seam planning.

Tile calculator — free tool for ceramic, porcelain & stone floors. Get tile count, boxes, grout bags & adhesive needed for any room size.

Laminate flooring calculator — free plank & box estimator with underlay. Enter room size and plank dimensions for instant material list.

Free stair calculator — enter total rise for instant step count, riser height, tread depth & stringer length. Meets UK Building Regulations.

Free stair stringer calculator — get stringer length, count & layout for any staircase width. Covers 50×250 & 50×300 mm timbers.

Rise over run calculator — free slope tool. Get ratio, percentage, angle & description instantly. Works for stairs, ramps & roofs.

Free spiral staircase calculator — enter diameter & floor height for tread count, rise per step & rotation. Meets building regs.

Free stair landing calculator — split flights with intermediate landing. Get steps per flight, landing height & total run.

Free baluster spacing calculator — get exact count and uniform spacing for stair and deck balustrades. Complies with Building Regulations.