Concrete Cost Estimator

The dry volume factor of 1.54 accounts for the bulking of sand and voids in coarse aggregate. Wet concrete has less volume than the sum of dry ingredients because the fine particles fill voids between coarse particles.

M20 (1:1.5:3) is the minimum for reinforced concrete per IS 456. M25–M30 for general RCC works, M35–M45 for high-rise and prestressed, M50+ for special applications. C grades are Eurocode equivalents.

For M20 (1:1.5:3): dry volume = 1.54 m³, cement proportion = 1/5.5 × 1.54 × 1440 = 403 kg ≈ 8 bags (50 kg each) per cubic meter of concrete.

Waste factor is typically 5% for site-mixed concrete and 8–10% for pumped concrete. Higher wastage occurs in thin sections, intricate formwork, and foundation works. Allow up to 15% for piling.

Rate analysis includes: materials (cement, sand, aggregate, water, admixtures), labor (batching, mixing, placing, finishing), plant (mixer, vibrator), transport (if RMC), and contractor overheads and profit.

Nominal mix uses fixed ratios (e.g., 1:1.5:3 for M20). Design mix is proportioned based on material testing to achieve target strength efficiently. Design mix is mandatory for M25+ per IS 456.

Plasticizers (0.5–1.5% of cement weight) can reduce water content by 10–15%, improving strength and reducing cement requirement. Superplasticizers allow higher workability without strength loss but add ₹50–200 per m³.

RMC is economical for volumes > 30 m³, where quality control is critical, or when site space for mixing is limited. For small works (< 10 m³), site mixing is usually more economical.