Home & DIY Calculators
Paint, concrete, tile, flooring, mulch, gravel, roofing, drywall, BTU and stair calculators that estimate materials and costs for your next DIY project.
51 free tools
Paint Calculator
Work out how much paint a room needs from its length, width and height, minus doors and windows, with coats, coverage rate and the number of cans to buy.
Concrete Calculator
Calculate concrete volume for slabs, footings, columns and round tubes in cubic yards and cubic metres, then convert it to 40, 60 or 80 lb bags or truck loads.
Tile Calculator
Calculate how many tiles and boxes you need for floors or walls from tile size, grout joint width and a waste allowance, across as many surfaces as you like.
Flooring Calculator
Add up several rooms, apply a waste allowance and divide by the coverage printed on the pack to get the boxes of laminate, vinyl, hardwood or carpet you need.
Mulch Calculator
Work out mulch volume for rectangular, circular or triangular beds in cubic yards, cubic metres and bags, and compare bagged mulch against a bulk delivery.
Gravel & Aggregate Calculator
Calculate gravel, crushed stone, sand or topsoil for a driveway or path — volume in yards and metres, weight in US tons and tonnes, and the delivered cost.
Roofing Calculator
Turn a building footprint and roof pitch into roof area, roofing squares, shingle bundles, underlayment rolls, ridge cap and starter strip with waste added.
Drywall Calculator
Work out drywall sheets for a room from wall and ceiling area, plus the joint compound, tape and screws needed, using standard trade estimating ratios.
Board Foot Calculator
Calculate board feet for a whole lumber cut list from thickness, width and length, with quantities, a cubic-metre equivalent and cost per board foot.
Fence Calculator
Turn a fence run and post spacing into post, rail, picket and panel counts, with gate openings deducted and the concrete needed for every post hole.
Wallpaper Calculator
Calculate wallpaper rolls from room size, roll width and length, and pattern repeat — with pattern matching, trim allowance and the real waste percentage shown.
BTU Calculator
Estimate the BTU per hour a room needs for heating and cooling from its size, ceiling height, insulation, sun exposure and climate zone, with kW and AC tonnage.
Stair Calculator
Work out riser height, tread depth, total run and stringer length from a total rise, and check the result against US, UK and Australian stair code limits.
Electricity Cost Calculator
Calculate what appliances cost to run: enter watts, hours per day and days per week to get kWh and cost per day, month and year, for a whole list of devices.
Deck Calculator
Work out decking boards, joists, beams, posts, railing and screws from your deck size, board width and joist spacing, with waste, board feet and cost.
Brick Calculator
Calculate how many bricks or blocks a wall needs from its size and the unit dimensions, with mortar joints, door and window deductions, waste and mortar volume.
Mortar Calculator
Calculate bags of mortar mix from a brick or block count or from wall dimensions, plus cement, lime and sand volumes for ASTM type N, S, M and O mixes.
Paver Calculator
Calculate how many pavers a patio needs plus base gravel, bedding sand, edge restraint and polymeric sand, with pattern waste for herringbone and running bond.
Rebar Calculator
Calculate slab rebar: bars each way from your spacing, lap splices at 40 bar diameters, total linear feet, tie intersections and weight from the ASTM bar table.
Asphalt Calculator
Calculate asphalt tonnage for a driveway from area, compacted thickness and density, for rectangular, L-shaped and circular areas, with cubic yards and cost.
Insulation Calculator
Work out insulation batts or blown-in bags from wall or attic area, deduct the framing, and check the R-value your thickness achieves against a target.
Siding Calculator
Calculate siding squares and boxes from wall perimeter, height and gables, less doors and windows, plus starter strip, J-channel, corner posts and soffit.
Baseboard & Trim Calculator
Work out baseboard, crown, chair rail and shoe moulding from room size or perimeter, less doorways, converted into stock lengths with waste, joints and mitres.
Wall Framing Calculator
Count studs, corner and T studs, kings, jacks and cripples, plate and header lengths and board feet from your wall length, stud spacing and openings.
Retaining Wall Calculator
Calculate retaining wall blocks per course and total courses including the buried base, plus cap blocks, pallets, base gravel, drainage stone and backfill.
Sod Calculator
Add up an irregular lawn from rectangles, circles and triangles, then convert it into sod slabs, rolls and pallets with a waste allowance and cost per pallet.
Grass Seed Calculator
Calculate grass seed from lawn area and grass type using published new-lawn and overseeding rates, plus the starter fertiliser to hit a target nitrogen rate.
Solar Panel Calculator
Work out the solar system size, panel count, roof area and annual kWh your home needs from your daily use and peak sun hours, then see the simple payback.
Generator Size Calculator
Add up running and starting watts for the appliances you want to back up, then size a generator in watts, kW and kVA and estimate runtime on one tank of fuel.
LED Savings Calculator
Compare old bulbs with LEDs on energy, cost and lifespan. See annual kWh, yearly saving, payback in months and how many replacement bulbs you avoid buying.
Natural Gas Cost Calculator
Convert therms, CCF, cubic metres and kWh of gas, apply flat or tiered rates with a standing charge and tax, and price the cost of running a gas appliance.
Water Bill Calculator
Price a metered water bill with tiered rate blocks, a sewer charge, fixed fee and tax, then see the effective cost per unit and what using less would save.
Firewood Calculator
Convert a firewood stack into full cords, face cords and cubic metres, work out the price per cord, and compare its heat value against gas and electric heating.
Pool Volume Calculator
Calculate swimming pool volume in gallons and litres for rectangular, round, oval and kidney pools, plus fill time, pump turnover and chemical dose scaling.
Cooking Measurement Converter
Convert cups, tablespoons, teaspoons, fluid ounces, millilitres, grams and ounces for flour, sugar, butter and more, with US, metric and imperial cup sizes.
Recipe Scaler
Paste an ingredient list and scale every quantity to a new serving count. Handles mixed numbers and fractions like 1 1/2 and ¾, with tidy fraction output.
Baking Pan Conversion Calculator
Swap one baking pan for another safely. Compare areas and batter volumes for round, square, rectangular, loaf and bundt pans and get the recipe multiplier.
Roast Cooking Time Calculator
Work out roasting time by weight for turkey, chicken, beef, pork, lamb and ham, with resting time, target internal temperature and a start time to aim for.
Coffee to Water Ratio Calculator
Solve any two of coffee dose, water and brew ratio, with presets for pour-over, drip, French press, AeroPress, espresso and cold brew, in grams, ml or fl oz.
Crown Molding Calculator
Total your crown molding run from a list of wall lengths, get the sticks to buy with a cutting plan, and read the exact compound miter and bevel saw settings.
Countertop Calculator
Add up countertop square footage from straight, L and U runs plus islands, subtract sink and cooktop cut-outs, add backsplash, and cost material, edge and seams.
Carpet Calculator
Lay a room out against a 12 ft, 15 ft or 3.66 m roll to get drops, seam positions, running feet and true square yards, plus underlay, gripper and total cost.
Gutter Calculator
Total your gutter run from eave lengths, size 5 and 6 inch K-style or half-round against roof area and rainfall, and count downspouts, hangers, elbows and corners.
Attic Ventilation Calculator
Work out the net free area your attic needs under the 1:300 or 1:150 rule, split it between intake and exhaust, and convert it into soffit, ridge, box or gable vents.
Lawn Fertilizer Calculator
Work out how much fertiliser your lawn needs from the N-P-K analysis and a target nitrogen rate, with bag counts, spreader calibration and an annual programme total.
Pool Chemical Calculator
Dose chlorine, pH, alkalinity, calcium, stabiliser and salt from your test results and pool volume, and check water balance with the Langelier Saturation Index.
Raised Bed Soil Calculator
Work out how much soil your raised beds need in cubic feet, cubic yards, litres and bags, then split it by mix ratio into compost, peat or coir and vermiculite.
Rainwater Harvesting Calculator
Estimate rainwater harvest from roof area and monthly rainfall, run a month-by-month tank balance, and size storage for a dry spell at your daily demand.
Sprinkler Run Time Calculator
Work out sprinkler precipitation rate from head spacing and flow, then get run minutes per zone with a cycle-and-soak schedule matched to your soil and slope.
Water Heater Size Calculator
Size a water heater from your peak-hour fixture use: tank first-hour rating and recovery, or tankless GPM at your design temperature rise, with a pass or fail verdict.
Curtain Fabric Calculator
Work out curtain fabric from track width, drop and fullness: number of widths, cut length rounded to whole pattern repeats, lining yardage and total cost.