📘 Based on IS 10262·📖 Read: Cement, sand & steel for 1000 sqft house

About this calculator

The Material Estimator computes material quantities — concrete (cement, sand, aggregate), brickwork (bricks, mortar), plastering, tiling, painting, flooring screed — for a given area or volume. Outputs are aligned to IS 1200 measurement conventions and apply standard wastage allowances per CPWD / NBO data.

Use it during quantity surveying / BOQ preparation, to verify a contractor's running bill, or to estimate material orders for a small private build.

Methodology

Concrete — nominal mix proportions

Per IS 456 Table 9 (nominal mixes): M5 1:5:10, M7.5 1:4:8, M10 1:3:6, M15 1:2:4, M20 1:1.5:3 (cement : fine aggregate : coarse aggregate by volume). Bulk densities: cement 1,440 kg/m³, sand 1,600 kg/m³, aggregate 1,500 kg/m³. For 1 m³ wet concrete: dry volume = 1.54 × 1 = 1.54 m³ (accounts for voids). M20: cement = 1.54 / 5.5 × 1,440 = 403 kg ≈ 8.06 bags; sand = 1.54 / 5.5 × 1.5 × 1,600 = 672 kg; aggregate = 1.54 / 5.5 × 3 × 1,500 = 1,260 kg.

Brickwork

Brick size (nominal): 230 × 115 × 75 mm (with mortar joint). Bricks per m³ of brickwork: 1 / (0.230 × 0.115 × 0.075) = 504 ≈ 500 bricks. Mortar per m³ of brickwork: 0.30 m³ (1:6 cement-sand). For a 230 mm thick wall: bricks per m² = 60 (with 10 mm mortar joint). Wastage: 5%.

Plastering

Internal plaster (12 mm thick, 1:6 mix): per m² wall = 0.012 m³ wet → 0.018 m³ dry → cement 1.86 kg / 0.04 bag, sand 0.018 m³. External (15-20 mm, 1:4 or 1:5): per m² = 0.018 m³ wet → 0.025 m³ dry. Wastage: 10%.

Painting / coating

Distemper: 1 L covers 5-8 m² (single coat). Acrylic emulsion: 12-15 m² per L. Cement primer: 8-10 m² per L. Two-coat external + two-coat internal is the norm. Apply 10% wastage. Add a primer coat for new walls (mandatory per IS 109 for distempers).

Worked example — 1,000 sqft (93 m²) RCC slab, 150 mm thick, M20

Slab volume: 93 × 0.15 = 13.95 m³. M20 cement: 13.95 × 8.06 = 112 bags (50 kg) at ₹385/bag PPC = ₹43,120. Sand: 13.95 × 0.42 m³ = 5.86 m³ at ₹2,000/m³ = ₹11,720. Aggregate (20mm): 13.95 × 0.84 = 11.72 m³ at ₹1,800/m³ = ₹21,096. Steel @ 80 kg/m³: 1,116 kg × ₹70 = ₹78,120. Add 5% wastage on cement / sand / aggregate. Total material cost (RCC slab only): ~₹1.55 L. Labour adds another 25-30%. Total slab cost: ~₹2.0 L for a 1,000 sqft G+1 floor's RCC slab.

Frequently asked questions

Why is dry volume 1.54× wet volume for concrete?

Aggregate and sand have voids (intergranular spaces) that fill with water + cement paste during mixing — so the dry sum of constituent volumes is higher than the final wet volume. Empirical factor: 1.54 for nominal concrete mixes (range 1.50-1.57). The 0.54 factor represents the volume of voids in dry aggregate that gets filled with cement paste + water. Without this factor, a quantity calc would underestimate cement / sand / aggregate by ~35%.

How many bags of cement are in a 1 m³ M20 mix?

Per nominal mix 1:1.5:3, cement = 403 kg / m³ wet concrete = 8.06 bags (50 kg). Add wastage 3-5% → 8.5 bags. For 100 m³ of M20: 850 cement bags, 154 m³ sand, 308 m³ aggregate. Always cross-check with site mix-design (IS 10262) — actual content can be 380-430 kg depending on aggregate gradation, w/c, and admixture.

Wastage allowance — what's typical?

Cement: 3-5%. Sand / aggregate: 10% (more loss in handling / spillage). Bricks: 5-7%. Steel: 3% routine, 5% complex detailing. Tiles: 8-10% (cuts at edges). Paint: 10%. Always discuss with the contractor and tighten if their crew is experienced — younger crews can run 12-15% on bricks and aggregate.

Can I mix M20 by hand without a mix design?

For small jobs (< 5 m³), yes — nominal mix 1:1.5:3 by volume is acceptable per IS 456 Cl. 9.1.1 for grades up to M20. Use measuring boxes (farma), not buckets. Larger / structural / higher-grade jobs (M25+) require IS 10262 design mix verified at site by trial cubes.

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