Free calculators, unit converters, and reference guides for construction and home renovation. No sign-up required.
Convert lengths, areas, volumes, weights, and more.
10 tools 🧮Estimate paint, tile, concrete, and other materials.
17 tools ⚡Wire sizing, circuit breakers, lighting calculators.
5 tools 🔥Boiler, radiator, and pipe sizing tools.
4 tools 📐Room area, stairs, roof pitch, and squareness checks.
6 tools 📋Standard sizes, codes, and material references.
9 toolsCalculate aerated concrete (AAC) blocks needed for a wall based on wall area, block dimensions, and mortar joint.
Open →Convert between degrees, radians, percent slope, and ratio (run:rise). Useful for roof pitches, ramps, and grading.
Open →Convert area between metric and imperial units: square metres, square feet, square inches, acres, and hectares.
Open →Estimate the boiler power (kW) you need based on floor area, ceiling height, insulation level, and climate.
Open →Calculate bricks needed for a wall based on wall area, brick size, and mortar joint thickness. Standard sizes supported.
Open →Pick the correct circuit breaker for a given continuous load, with NEC 80% rule and IEC adjustments. Supports general, dedicated, and motor circuits.
Open →Calculate concrete volume and mix quantities (cement, sand, gravel) for slabs, strip footings, and columns.
Open →Concrete strength grades with compressive strength (MPa and psi), mix ratios, and typical uses — from C15 to C50.
Open →Typical widths, heights, and thicknesses for residential doors in the US, UK, and EU — interior and exterior.
Open →Calculate drywall sheets needed plus metal profiles, screws, and joint tape for a wall of given dimensions.
Open →Convert energy between joules, kilojoules, kilowatt-hours, kilocalories, and BTU. Exact factors for engineering and cooking contexts.
Open →Calculate how much your appliance costs per month and per year based on power, usage hours, and electricity tariff.
Open →Calculate posts, pickets, rails, and post length for a wood or composite fence. Supports gate deduction.
Open →Typical frost depth for the US, Canada, UK, and Europe — used for footing depth and buried water-line placement.
Open →Glossary of common construction, renovation, and trade terms — framing, materials, finishes, electrical, and plumbing. Clear definitions with categories.
Open →Calculate insulation packs needed (mineral wool, EPS, XPS, PIR) for walls, roofs, or floors, with R-value estimates.
Open →Calculate laminate or parquet boards and packs needed for a floor, including waste allowance for cuts.
Open →Convert lengths between metric and imperial units: metres, centimetres, millimetres, kilometres, inches, feet, yards, miles.
Open →Calculate lumens and watts needed to light a room based on area, room type, and source efficacy (LED, CFL, halogen, incandescent).
Open →Calculate the linear metres of linoleum roll needed for a floor, including waste allowance.
Open →Calculate board feet and cubic metres from lumber piece dimensions, or work backwards to find piece counts from a volume budget.
Open →Calculate the cement and sand needed for laying brick or block, with standard mix ratios (1:3, 1:4, 1:6).
Open →Estimate how much paint you need based on wall area, number of coats, and coverage. Get litres needed plus can counts.
Open →Calculate required pipe diameter from water flow rate and maximum velocity. Suggests nearest standard nominal size (DN).
Open →Calculate plaster (kilograms and bags) needed based on wall area and thickness.
Open →Convert power between watts, kilowatts, megawatts, horsepower, and BTU/h. Useful for engines, heaters, and appliances.
Open →Convert pressure between bar, PSI, pascal, kilopascal, megapascal, atmosphere, and mmHg. Exact factors.
Open →Calculate primer needed for walls, accounting for coats, coverage, and surface absorbency (smooth, textured, porous).
Open →Calculate the weight of putty or spackle needed to fill and smooth walls before painting.
Open →Calculate the number of radiator sections needed for a room based on volume, insulation, climate, and section heat output.
Open →Steel reinforcement bar sizes: US imperial (#3, #4, #5, #6, #8) and metric (⌀8–⌀25 mm) with diameter, mass per metre, and cross-section area.
Open →Calculate roof pitch from rise and run, degrees, or ratio. Get pitch in degrees, percent slope, ratio, and rafter length.
Open →Calculate roof area and material needed for gable, hip, or flat roofs. Supports metal tile, corrugated sheet, and bitumen shingle.
Open →Calculate the floor area of rectangular or L-shaped rooms with optional deductions for windows and doors.
Open →Calculate vinyl or wood siding panels (and boxes) needed for an exterior wall, with waste allowance.
Open →Convert speed between metric and imperial units: km/h, mph, metres per second, knots, and feet per second.
Open →Check if a corner is square using the 3-4-5 method. Enter two sides and the measured diagonal to see the exact expected value and deviation.
Open →Calculate the number of steps, exact riser height, tread depth, and incline angle for a staircase between two floors. Includes code-compliance check.
Open →Typical stud spacing for residential and commercial framing in the US, UK, Canada, and Europe. Imperial and metric values, use cases, and exceptions.
Open →Convert temperature between Celsius (°C), Fahrenheit (°F), and Kelvin (K). Exact formulas, instant conversion.
Open →Calculate how many tiles you need for your floor or wall, including waste allowance for cuts and breakage.
Open →Estimate pipe length, heat output, and number of circuits for wet underfloor heating. Supports bathroom, kitchen, living, bedroom room types.
Open →Calculate voltage drop across a wire run based on length, current, gauge, and system voltage. Checks against the 3% recommended limit.
Open →Convert volume between metric and imperial units: litres, millilitres, cubic metres, cubic feet, US and UK gallons, quarts, and pints.
Open →Calculate total wall area, then subtract windows and doors to get the net paintable or wallpaperable area.
Open →Typical thicknesses and layer breakdowns for common interior and exterior wall types — drywall, brick, cavity walls, metal stud, concrete. Plus guidance on drilling safely.
Open →Calculate wallpaper rolls needed for your room, including pattern repeat and waste allowance.
Open →Convert weight and mass between metric and imperial units: kilograms, grams, pounds, ounces, metric tons, and US short tons.
Open →Typical widths and heights for residential windows in the US (double-hung, casement, picture), UK (casement, sash), and EU (tilt-turn).
Open →Electrical wire color codes for US residential and commercial, EU IEC, and UK (post-2004 vs legacy). Hot, neutral, ground identification.
Open →Pick the right wire size (AWG or mm²) for your circuit based on current load and installation method. Based on NEC and IEC ampacity tables.
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