The most-searched questions on concrete, materials, house cost, FSI rules, structural design and finishes — answered, with links to the calculators that do the maths.
Enter the wet dimensions of your element (length, width and thickness/depth) in metres or feet to get the wet volume. The calculator multiplies that by the dry-volume factor of about 1.54 to get the dry material volume, then splits it by the chosen grade's mix ratio (for example 1:1.5:3 for M20). Results come out as 50 kg cement bags and cubic feet, cubic metres or brass for sand and aggregate.
Concrete material calculator →It divides the dry volume into proportional parts based on the grade's nominal mix ratio. The part volume is the total dry volume divided by the sum of the ratio parts (cement + sand + aggregate); each material is then that part volume multiplied by its number of parts. For M20 (1:1.5:3) the parts sum to 5.5.
Mix design calculator →First find the wet volume (L × W × D). Multiply by 1.54 for the dry volume. Divide the dry volume by the sum of the mix-ratio parts to get one part. Cement bags = cement volume ÷ 0.0347 m³ (one bag). Sand and aggregate volumes are their parts multiplied by the single-part volume, then converted to cft or brass as needed.
Concrete material calculator →Enter length, width and depth in metres; the tool returns the volume in cubic metres (m³, sometimes written 'cum'). This metric output is what ready-mix concrete (RMC) plants use for batching and what most structural drawings specify.
Concrete material calculator →M20 uses the nominal ratio 1:1.5:3 (cement : sand : aggregate). For each 1 m³ of finished concrete, the dry volume is 1.54 m³, which works out to roughly 8 bags of cement, about 0.42 m³ (≈15 cft) of sand and about 0.84 m³ (≈30 cft) of aggregate. M20 is the most common grade for residential RCC.
Mix design calculator →Enter dimensions in feet to get the volume in cubic feet (cft). This is the unit local suppliers in India most often use when quoting and delivering sand, M-sand and crushed aggregate, so working in cft makes ordering straightforward.
Concrete material calculator →M25 has a characteristic compressive strength of 25 N/mm² at 28 days and is often quoted as a 1:1:2 ratio, needing roughly 11 bags of cement per m³. Note that under IS 456, M25 and above are design mixes, so 1:1:2 is an approximation for estimating only — structural M25 should use a proper IS 10262 mix design.
Mix design calculator →About 1.54 for concrete (commonly cited as 1.52–1.57). It accounts for the air voids between dry particles that get filled when water is added and the mix is compacted, so the loose dry materials occupy more space than the finished concrete. It is a widely used site rule of thumb, not a fixed code constant.
Why 1.54? →It takes the dry volume and the mix ratio, computes the sand and aggregate fractions, and converts them to cubic feet. Working in cft lets you check quantities directly against local truck-load sizes and supplier quotes.
Concrete material calculator →It takes the cement volume in cubic metres and divides by the volume of one bag (0.0347 m³), then rounds up to the next whole bag so you don't fall short on site. Equivalently, multiply the cement volume by 1440 kg/m³ and divide by 50.
Concrete material calculator →For 1 m³ of M20: dry volume = 1 × 1.54 = 1.54 m³; parts = 1 + 1.5 + 3 = 5.5. Cement = 1.54÷5.5 = 0.28 m³ ≈ 8 bags (≈403 kg). Sand = 0.28 × 1.5 = 0.42 m³ (≈14.8 cft). Aggregate = 0.28 × 3 = 0.84 m³ (≈29.7 cft).
Concrete material calculator →Multiply the slab area (length × width) by its thickness (often 0.125 m / 5 inches) for the wet volume. Apply the 1.54 factor, pick the grade, and read off cement bags, sand and aggregate — adding a wastage allowance of around 5–10% for site loss.
Concrete slab calculator →Because loose, dry ingredients contain substantial air voids — roughly 30–34% between aggregate particles, plus shrinkage as the mix wets and compacts. Multiplying the wet volume by about 1.54 ensures you buy enough dry material to yield the finished volume you need.
Why 1.54? →M15 is a lean grade with a nominal ratio of 1:2:4 (parts sum to 7). It is used for non-structural work such as levelling courses, sub-base under floors, and footpaths — not for load-bearing RCC.
Mix design calculator →Divide the cement volume by 0.0347 m³ (one bag), or use the density method: cement volume × 1440 kg/m³ gives the weight in kg, then divide by 50 for the bag count. Always round up to whole bags.
Concrete material calculator →A standard commercial cement bag in India is 50 kg. This is the baseline unit for site mixing and material pricing.
Brass is a traditional Indian volume unit equal to 100 cubic feet (2.832 m³), used mainly in states like Maharashtra and Gujarat for sand and aggregate. To convert, work out the volume in cubic feet and divide by 100.
cft, brass & m³ units →A tool that estimates materials using fixed volumetric ratios (M10, M15, M20) recognised under IS 456, rather than the lab trials of a design mix. Nominal mixes are convenient for small and routine work; IS 456 permits them up to about M20.
Mix design calculator →Commonly used dry bulk densities are: cement (OPC) about 1440 kg/m³; sand about 1550 kg/m³ (site range ~1450–1650); coarse aggregate about 1500 kg/m³ (range ~1450–1550). These convert material volumes into site weights.
Method & constants →M20's nominal volumetric ratio is 1:1.5:3 — 1 part cement, 1.5 parts fine sand (or M-sand), and 3 parts graded coarse aggregate (typically a 10 mm and 20 mm mix).
Mix design calculator →M10 uses a nominal ratio of 1:3:6 (parts sum to 10). For 1 m³ of concrete it needs roughly 4.4 bags of cement — a lean mix suited to levelling layers and non-load-bearing bases rather than structural members.
Mix design calculator →One 50 kg OPC bag occupies about 1.226 cubic feet (0.0347 m³). This is the figure used to calibrate the measuring boxes (farmas) used to batch materials on site.
cft, brass & m³ units →It computes the wet volume in cubic metres, then multiplies by a regional RMC rate (indicatively around ₹4,500–6,000/m³, which varies by city and grade) to help compare on-site batching against ordering transit-mixer concrete.
Concrete material calculator →Water weight (litres) = cement weight (kg) × water-cement ratio. For structural concrete under IS 456 the ratio is typically about 0.40–0.55, chosen for the exposure condition. Lower ratios give stronger, more durable concrete; adding extra water on site weakens it.
Water-cement ratio →Find the aggregate volume in cubic metres, multiply by its bulk density (about 1500 kg/m³) for the weight in kg, then divide by 1000 to get metric tonnes for ordering.
Concrete material calculator →Yes — our house construction cost calculator includes a free Excel (XLSX) download that lays out the per-sqft estimate and cost-head breakdown, so you can keep and edit it. It's an estimate to plan with, not a fixed quote.
House cost calculator →It applies per-sqft thumb-rules to your total built-up area. As a common rule, each sqft needs roughly 0.4 bags of cement, about 1.8 cft of sand, about 1.35 cft of aggregate and about 4 kg of steel. These are planning figures; exact quantities come from a detailed take-off.
Raw material calculator →Indicatively, residential construction runs about ₹1,500–1,800/sqft for basic spec, ₹1,800–2,200 for standard, and ₹2,300–3,000+ for premium and luxury finishes (2025–26). City, design, soil and specification swing the real figure considerably.
House cost calculator →It organises the project into sequential cost heads — excavation, foundation RCC, structural frame, masonry, plaster, plumbing and electrical, and finishes — and links quantity take-offs to rates so the totals update as you adjust them.
House cost calculator →It tracks structural quantities (steel weight, concrete volume, brick counts, plaster area) against material rates and labour, producing a bill of quantities (BOQ) and a project total.
BOQ estimator →As an indicative figure, a standard single-storey 1,000 sqft home runs about ₹15–18 lakh for a standard frame and basic finishes, assuming normal site and foundation conditions. Enter your area and quality for an estimate.
House cost calculator →Map your built-up area against per-sqft thumb-rules: cement ~0.4–0.45 bags, steel ~3.5–4.5 kg, sand ~1.6–1.8 cft, aggregate ~1.2–1.4 cft, and bricks ~8 per sqft. Use these to plan, then refine with a detailed take-off from drawings.
Raw material calculator →Indicatively, a G+1 duplex of about 2,000 sqft built-up runs roughly ₹32–40 lakh in many metro suburbs for structure plus standard finishes. The figure varies widely with city, spec and design.
House cost calculator →Roughly 60–70% of a typical Indian build budget is raw materials, with labour, approvals and contractor margin making up the rest. Cement and steel alone are a large part of the material spend.
House cost calculator →As a thumb-rule (about 0.4–0.45 bags/sqft), roughly 480–540 bags across all stages — footings, columns, plinth beams, slab, brickwork and plaster. The exact figure depends on the structural design.
Raw material calculator →It isolates the cost of the bare structural frame — excavation, foundation, RCC columns, beams, slabs and brick masonry — before finishing. The grey structure is typically about 45–50% of the turnkey budget.
House cost calculator →A G+2 structure needs deeper foundations and heavier column steel. For about 1,500 sqft per floor (≈4,500 sqft total), the structural budget indicatively starts around ₹70 lakh and can exceed ₹90 lakh depending on soil and spec.
House cost calculator →By applying regional material prices, transport and local labour wages. For example, skilled-mason day rates and river-sand costs differ between cities, so a per-sqft rate is adjusted up or down accordingly. Use a local rate in the calculator's editable rate field.
House cost calculator →It splits the total into stage-wise funding: indicatively ~10% excavation and foundation, ~35% RCC structure, ~25% brickwork and plaster, and ~30% flooring, plumbing, electrical and paint. Aligning cash to stages prevents mid-build stalls.
Estimate your cost (guide) →For a typical residential build it is roughly even — about 50% on the structural grey frame (foundation, columns, slabs, brickwork) and about 50% on finishing (tiles, paint, woodwork, plumbing, electrical, sanitaryware).
House cost calculator →FSI is the total built-up area across all floors divided by the plot area: FSI = total built-up area ÷ plot area. Local municipal zoning sets the maximum permissible FSI for your area, which caps how much you can build. (We don't yet have an FSI calculator — this is the method.)
Floor Area Ratio (FAR) is the same measure as FSI — total built-up area divided by plot area. An FSI of 1.5 is the same as an FAR of 1.5 (sometimes written as 150% as a percentage). The terms are used interchangeably across different states.
Multiply your net plot area by the FSI coefficient set by your local authority. For a 2,000 sqft plot with an FSI of 1.5, the maximum built-up area across all floors is 3,000 sqft.
Mathematically none — both are total built-up area divided by plot area. FSI (Floor Space Index) is the common term in western and southern states; FAR (Floor Area Ratio) is used elsewhere, sometimes expressed as a percentage. The ratio itself is identical.
Start from the plot area, deduct the mandatory front, rear and side setbacks to get the buildable footprint, then apply the local FAR/FSI limit across floors. The lower of the setback-limited and FSI-limited area governs.
Plot coverage = (ground-floor footprint ÷ plot area) × 100. It measures how much of the plot the building covers at ground level. Residential zones commonly cap this around 45–60% to preserve open space.
Premium FSI lets you build beyond the base limit by paying a fee to the local authority, usually pegged to the ready-reckoner land value and a percentage factor, and often allowed only if the adjoining road meets a minimum width. Rules vary by city.
Local authorities set FSI by infrastructure capacity — adjoining road width, population density, sewage and water capacity, and proximity to transit. Wider roads and better infrastructure generally allow higher FSI.
Add a loading factor (commonly 25–35%) to the carpet area. The loading covers your share of common spaces — lobbies, lifts, stairs. Super built-up = carpet area × (1 + loading factor).
Loading factor (%) = ((super built-up area − carpet area) ÷ carpet area) × 100. Under RERA, developers must disclose carpet area, making this comparison transparent for buyers.
Setbacks are the mandatory open distances between a building and the plot boundaries (front, rear, sides), set by local bye-laws based on plot size and building height for light, ventilation and fire safety. Tools like BBMP's bye-laws specify these for Bengaluru.
Under RERA, carpet area is the net usable floor area within the inner walls of a unit. It includes internal partition walls but excludes common areas, balconies, open terraces and external structural columns.
Most municipal corporations publish property details on their property-tax portals; logging in with your Property ID or assessment number typically shows the recorded built-up area. The exact portal varies by city.
Modern municipal codes commonly exclude service and non-livable areas — stilt parking, lift shafts, underground water tanks and pump rooms — from the FSI count, though exact exemptions vary by local rules.
Building beyond the permitted FSI without a sanctioned premium allowance is illegal and can lead to penalties, fines, or demolition orders under the local town-planning rules. Always confirm limits before designing.
It divides the column's load by the soil's safe bearing capacity (SBC) to get the required footing area: area = load ÷ SBC. A larger load or weaker soil needs a bigger footing. Our calculator adds a self-weight allowance and gives a buildable size, with the caveat that full footing design needs an engineer.
Footing size calculator →Sum the dead, live and other loads on the column, add a safety allowance (about 10%), then divide by the soil's SBC for the required footing area. The depth and reinforcement are then designed separately per IS 456.
Column & footing calculator →It depends entirely on the column loads and soil, so there's no single answer; as a rough illustration, isolated footings on normal soil for a G+1 home are often around 1.2 × 1.2 m at 1.2–1.5 m depth. Always size from the actual load and a soil test, confirmed by an engineer.
Footing size calculator →A BBS lists each bar's shape, count and cutting length, then its weight via the d²/162 rule. Cutting length accounts for hooks and bend deductions (about 2d per 90° bend) per IS 2502. Our BBS calculator does this for standard shapes.
Bar bending schedule →Find the bar count (footing width ÷ spacing, both ways), the cutting length of each bar (clear dimension minus cover, plus hooks), then weight via d²/162 kg/m. Sum across both directions for the total.
Bar bending schedule →A common safe size is 230 × 230 mm (9″ × 9″) or 230 × 300 mm, often with 4–6 bars of 12 mm and 8 mm stirrups at ~150 mm. The correct size is always a structural-design decision based on load.
Column & footing calculator →Slab thickness is governed by the span-to-depth ratio in IS 456: minimum depth = effective span ÷ (basic ratio × modification factor). For typical residential floors this gives about 125–150 mm. Bending and steel are then designed to the loads.
Concrete slab calculator →You enter bar diameter and total length; it applies the d²/162 kg/m unit weight and totals the result in kg, quintals or tonnes. It covers standard diameters from 8 mm to 25 mm.
Bar bending schedule →From steel's density (7850 kg/m³). The weight of a 1 m round bar of diameter d (mm) simplifies to d²/162.28 kg/m. For example a 12 mm bar weighs 12²/162 ≈ 0.889 kg/m.
TMT bars →Place columns on a structural grid at major wall intersections, around stairs and along load lines, keeping clear spans within about 3–5 m to avoid oversized beams. The final layout is a structural-design decision.
Column & footing calculator →A G+2 structure typically needs about 1.8–2.4 m of foundation depth to reach firm subsoil and avoid seasonal soil movement, but the exact depth depends on the soil investigation and loads. Confirm with an engineer.
Footing size calculator →Beyond the bearing area, a full design checks two-way (punching) shear, bending moment and development length per IS 456 to set the footing depth and reinforcement. This is engineering design — our footing tool sizes the footprint only.
Footing size calculator →A trapezoidal footing is a lower rectangular block plus an upper sloped (truncated-pyramid) section. Total volume = (L × W × h) + (H/3) × [A₁ + A₂ + √(A₁·A₂)], where A₁ and A₂ are the lower and upper areas. (We don't have a dedicated tool for this yet; this is the formula.)
As rough estimating ratios of concrete volume: slabs ~0.7–1.0%, beams ~1.0–2.0%, and columns ~1.5–3.0%. Actual steel comes from the structural design, not these ranges.
Bar bending schedule →Find the inner core (member dimension minus cover on each side), then cutting length = 2 × (core length + core width) + hooks − bend deductions. A common setup adds 2 × 10d for 135° hooks and subtracts for the 90° bends.
Bar bending schedule →Typical IS 456 clear cover: slabs ~20 mm, beams ~25 mm, columns ~40 mm, and footings ~50 mm. Cover protects the steel from corrosion and fire.
RCC →Lap length depends on bar diameter and stress. As common guidance, about 50d in tension zones (beams/slabs) and roughly 24d–40d in compression (columns), subject to the design code and conditions.
Rebar →Indicative SBC values: soft clay/alluvial ~50–100 kN/m², medium sand ~250–400, and hard rock far higher. These are starting points only — the real SBC for your site must come from a soil investigation.
Footing size calculator →A common allowance is about 1% of the steel weight, roughly 7–10 kg of binding wire per tonne of reinforcement.
Bar bending schedule →For residential RCC, spans are usually kept within about 5–7 m. Beyond ~7 m the bending moments grow quickly, needing deeper beams and more steel.
Column & footing calculator →Number of tiles = total floor area ÷ area of one tile, plus a wastage allowance (about 10% for a standard straight lay). Tiles are sold by the box, so round up to whole boxes.
Floor tile calculator →Enter room length and width and your tile size (for example 600 × 600 mm or 2×2 ft). It computes the area, the tile count with a breakage allowance, and the number of boxes from the pieces per box.
Floor tile calculator →Room dimensions, tile size, and the grout-joint gap (typically 2–5 mm), plus how cut tiles fall at the edges. Planning the layout reduces waste and keeps cut tiles away from the room's focal point.
Floor tile calculator →It uses the wall's running length and height to work out the number of precast panels and posts, then applies your local panel, post and installation rates for a cost. Panel sizes and prices vary by supplier, so it uses the rates you enter.
Precast wall calculator →From the running length and height get the wall area and volume; then add foundation excavation, plinth-beam concrete, support pillars (commonly every ~3 m), brick count and plaster. Estimate the brickwork and plaster with our calculators.
Brickwork calculator →Indicatively about ₹90–140 per sqft of wall area supplied and installed, which is often cheaper and faster than brick because it skips on-site plastering. Confirm current rates with local suppliers.
Precast wall calculator →It multiplies wall area by plaster thickness (often 12 mm internally) for the wet volume, applies the mortar dry-volume factor of 1.33, then splits by the mix ratio (such as 1:4 or 1:6) into cement and sand.
Plaster & mortar calculator →Divide the wall volume by the volume of one brick including its mortar joint. For standard modular bricks a common rule of thumb is about 500 bricks per cubic metre of wall, before a breakage allowance.
Brickwork calculator →Find the wall volume in cubic feet (length × height × thickness). For a 9-inch wall, a common figure is about 13.5 bricks per cubic foot; add ~5% for breakage to get the order quantity.
Brickwork calculator →A 12×12 ft room is 144 sqft. With 2×2 ft (4 sqft) tiles that's 36 tiles; adding a 10% allowance brings it to about 40 tiles.
Floor tile calculator →Use about 5–7% for simple square rooms, rising to 10–15% for diagonal layouts, large-format tiles, complex patterns or small rooms with many cuts.
Floor tile calculator →For 12 mm plaster in a 1:4 mix, roughly 5.5 kg of cement (~0.11 bag) and about 0.8 cft of sand per square metre of wall.
Plaster & mortar calculator →Grout (kg/m²) ≈ ((L+W)/(L×W)) × joint width × joint depth × a density factor (~1.8), with all tile dimensions in mm. Larger tiles and thinner joints use less grout. (We don't have a grout tool yet; this is the formula.)
It divides the wall area by the face area of one block (including joint). For an 8×8×16-inch block the face is about 0.89 sqft, giving roughly 1.12 blocks per sqft of wall. (We don't have a dedicated block tool yet; this is the method.)
Measure the total running length of the room's walls, subtract door openings, and divide by the skirting-tile length for the count. Add a small allowance for cuts at corners.
Floor tile calculator →For 12 mm plaster in a 1:4 mix, about 51 kg of cement (~1 bag) and roughly 4.5 cft of sand per 100 sqft of wall.
Plaster & mortar calculator →As a rule of thumb, mortar joints are about 25–30% of a brick wall's finished volume, with the bricks themselves making up the remaining 70–75%.
Brickwork calculator →For a 9-inch wall with standard fly-ash bricks, about 9.2 per sqft of wall; for a 4.5-inch partition, about 4.6 per sqft. Confirm against the actual brick size.
Brickwork calculator →AAC blocks are larger, lighter and reduce mortar use (fewer joints), and lower the structural dead load; red clay bricks have a long track record and lower unit cost. The choice trades material cost, speed and weight. (We don't have a comparison tool yet.)
Bricks (glossary) →To resist wind load, support pillars are commonly spaced about 2.5–3.0 m (8–10 ft) on centre, with pillars at all corners and gate openings.
Precast wall calculator →It multiplies the room perimeter by the tiling height, deducts door and window areas, and adds about 10% wastage for plumbing cutouts and trims to give the tile count.
Floor tile calculator →Consumption (kg/m²) ≈ ((L+W)/(L×W)) × joint width × joint depth × a density factor (~1.65 for epoxy), tile dimensions in mm. Epoxy is denser than cement grout, so it needs precise estimating. (No dedicated tool yet; this is the formula.)
For a 9-inch wall in a 1:6 mortar mix, roughly 3.5–4 bags of cement plus about 15–18 cft of sand to lay 1,000 standard bricks.
Brickwork calculator →About 1.33 for cement-sand mortar (lower than concrete's 1.54, because mortar has no coarse aggregate and bulks up less). It accounts for voids filled and compaction when water is added.
Plaster & mortar calculator →Indicatively about ₹350–500 per running foot for a ~6 ft precast fence, typically including pillars, panels, excavation and foundation backfill. Confirm with local suppliers as rates vary.
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