Enter your structural dimensions and concrete grade to get exact cement, sand, aggregate, and water quantities — per IS 10262:2019 nominal mix ratios, with 5% wastage built in.
Concrete material quantities are computed from the "dry volume" of the mix — because dry cement, sand, and aggregate occupy more space than the final compacted wet concrete due to voids between particles. IS 456:2000 commentary specifies a standard dry-volume conversion factor of 1.54x the wet volume. Getting this factor wrong, or using an outdated mix ratio, is the single most common source of both over-ordering and under-ordering.
A footing pour of 25 m³ at M20 grade (1:1.5:3 ratio) requires: dry volume 25 x 1.54 = 38.5 m³. Split across the ratio (1+1.5+3=5.5 parts): cement = 38.5/5.5 = 7.0 m³ approximately 200 bags; sand = 10.5 m³; aggregate = 21.0 m³. At current market rates, material cost is approximately Rs 1.16 lakh before wastage.
Top-performing sites verify the mix design against IS 10262:2019 for any grade M25 and above (design mix is mandatory above M20 per IS 456 Clause 9). For nominal mixes (M20 and below), the fixed ratios in IS 456 Table 9 are sufficient.
Estimators cross-check nominal mix quantities against IS 10262 design mix constants before finalising a BOQ, and separate the material order quantity (with wastage) from the theoretical quantity so wastage is tracked as its own line item.
Rebota's BOQ module computes these same IS 10262 quantities automatically from your project structural takeoff, links them to Purchase Orders, and compares actual site consumption from Daily Site Logs against the planned quantity in real time.
