Construction & Home
A quantity estimate is only as good as its assumptions about wastage, mix ratio and bulking, so those assumptions are inputs here rather than hidden constants. Where a figure is a convention rather than a measurement (the 1.54 dry-volume factor, for instance) the tool says so and links to where it comes from.
Land
Land Area CalculatorPlot area from field measurements, in every unit an Indian sale deed might use. An irregular four-sided plot needs a diagonal, because four sides alone do not determine an area.Land Unit ConverterLand area including the Indian units that genuinely vary by state. A bigha in Uttar Pradesh is nearly double a bigha in West Bengal, so the state matters more than the arithmetic.Carpet vs Built-Up vs Super Built-Up AreaCarpet, built-up and super built-up area converted between each other, with the effective rate on usable space. RERA requires carpet area to be disclosed, and the effective rate on it is usually a third above the quoted headline.FSI / FAR CalculatorPermissible built-up area from FSI and ground coverage. FSI limits total floor area and ground coverage limits the footprint, and it is the two together that decide how tall a building can be.
Materials
Concrete Volume CalculatorConcrete volume for a slab, column or footing, with wastage and the ready-mix load count. The dry volume of ingredients is larger than the wet concrete, which is the factor most quantity errors come from.Concrete Mix Ratio CalculatorCement, sand and aggregate for a concrete pour, with the 1.54 dry-volume factor exposed as an input rather than buried as a constant. M20 works out at 8.06 bags per cubic metre.Cement Bags CalculatorCement bags, sand and aggregate for a given volume and grade. The familiar figure of about eight bags per cubic metre for M20 falls straight out of the arithmetic rather than being quoted.Sand Quantity CalculatorSand for a concrete or mortar mix, including the bulking allowance. Damp sand occupies substantially more volume than dry sand, so ordering by the mix figure alone leaves you short.Aggregate Quantity CalculatorCoarse aggregate for a concrete mix, by volume and by weight. Aggregate does not bulk the way sand does, so the ordered quantity is the mix quantity.Brick CalculatorBrick count from wall dimensions, with mortar and its cement and sand. Counting the mortar joint as part of each brick is what makes the number come out right.Steel / Rebar Weight CalculatorReinforcement steel weight from bar diameter and length, with the exact figure alongside the familiar d²/162 shortcut. The exact denominator is 162.196.
Structural
Column and Footing Concrete CalculatorConcrete, steel and excavation for a set of isolated footings and the columns above them. Steel is estimated as a share of concrete volume, which is how quantities are checked on site.Staircase Design CalculatorStaircase geometry from the floor-to-floor height. Risers must be equal, so the height decides the count and the count decides the riser, not the other way round.Retaining Wall CalculatorBlock count for a segmental retaining wall, counting the buried base course that people forget. Drainage gravel behind the wall matters more than the blocks.
Finishing
Paint Quantity CalculatorPaint quantity from wall area, coverage and coat count. Coverage varies by a factor of two between a smooth sealed wall and fresh plaster, which is why it is an input rather than a constant.Primer and Putty CalculatorPrimer and wall putty quantity from area and coverage. Putty is applied in two thin coats and covers far less per kilogram than primer does per litre.Tile CalculatorTile count from floor or wall area, with wastage. Ten percent is the usual allowance and a diagonal or herringbone layout needs more, because every edge cut produces an offcut you cannot use.Tile Grout CalculatorGrout quantity from tile size, joint width and thickness. Smaller tiles need far more grout because there is more joint per square metre.Flooring Cost CalculatorFlooring cost from room dimensions, separating the area to cover from the area to order. Ordering the exact floor area is the standard mistake: every edge cut wastes part of a tile, and a second delivery rarely matches the first batch.Wallpaper CalculatorWallpaper rolls from wall area. A standard roll covers about five square metres in practice rather than the ten it measures, because pattern matching wastes a great deal.False Ceiling CalculatorFalse ceiling boards and the grid to carry them. Board count is straightforward; the framing runs at roughly three to four metres of channel per square metre, which is the larger part of the cost.
Outdoor
Plumbing
Water Tank Capacity CalculatorWater tank capacity and how long it lasts. A horizontal cylindrical tank does not fill linearly, so a dipstick reading half depth means considerably less than half full at the ends and exactly half in the middle.Rainwater Harvesting CalculatorRainwater harvest from a roof, with storage sized for the dry spell. A millimetre of rain on a square metre is exactly one litre, which makes the base calculation simple; the runoff coefficient is what varies.Septic Tank Size CalculatorSeptic tank sizing from household size and retention time. The tank holds two things: the sewage retained long enough to settle, and the sludge that accumulates between desludgings, and undersizing either causes failure.Water Pump Sizing CalculatorPump sizing from flow and head. Friction head is what undersized pipe adds, and it rises with the square of velocity, so a bore one size up often saves more energy than a better pump.
Electrical
Electrical Load CalculatorHousehold electrical load with a diversity factor. Sizing on connected load rather than diversified load overstates the requirement substantially, because everything is never switched on at once.Lighting and Lumens CalculatorLighting in lumens from room area and use. Watts measure power consumed and lumens measure light produced, and since LEDs the two have no fixed relationship, so buying by wattage no longer works.
HVAC
Energy
Solar Panel Sizing CalculatorSolar array sizing from daily consumption. Peak sun hours are the equivalent hours at full rated irradiance, not hours of daylight, which is the input people get wrong by a factor of two.Solar ROI and Payback CalculatorSolar payback with the two effects that pull against each other: tariffs rise, which helps, and panels degrade, which does not. Both compound, so a flat saving assumption is wrong within a few years.Inverter and Battery Sizing CalculatorInverter and battery sizing for a backup load. Nameplate battery capacity is roughly double the energy you need, because a lead acid battery should not be discharged past half and the inverter loses fifteen percent.Generator Sizing CalculatorGenerator sizing with motor starting surge. Sizing on running load alone is the classic error: a motor draws several times its rated power for a second or two on start, and a generator that cannot supply it will stall.
Cost
Construction Cost per Sq Ft CalculatorConstruction cost from built up area and a rate a square foot, with the finish level, contingency and approval fees separated. Roughly half of a house is structure and half is finishing, and it is the finishing half that varies by a factor of three between basic and luxury.Home Renovation Cost CalculatorRenovation cost with bathrooms and the kitchen priced separately from the general area, because wet areas cost several times what a dry room does per square foot and averaging them across the flat hides the real driver.Interior Design Cost CalculatorInterior fit-out cost by package, with the designer fee and GST shown as line items rather than folded into a per-square-foot number. Together they add roughly a quarter to a quoted fit-out, which is where most interior budgets are overrun before any choice is made.Modular Kitchen Cost CalculatorModular kitchen cost by running metre, with carcass, shutters, countertop and hardware priced separately. Shutters are the visible choice and the carcass is the one that decides whether the kitchen survives ten years of a wet climate.