5 professional guides in one — Slab, Column, Beam, Footing & Cement Bags. Get instant volume, cement bags, sand & aggregate quantities.
Concrete Slab Volume & Material Guide
Estimate concrete volume, cement bags, sand, and aggregate for floor slabs, roof slabs, and suspended slabs.
Concrete Column Volume & Material Guide
Estimate concrete volume and materials for square, rectangular, or circular reinforced concrete columns.
Column Shape
Concrete Beam Volume & Material Guide
Estimate concrete volume and materials for rectangular reinforced concrete beams — plinth beams, tie beams, and roof beams.
Concrete Footing Volume & Material Guide
Estimate concrete for pad footings, strip footings, and combined/raft foundations.
Footing Type
Cement Bags, Sand & Aggregate Guide from Volume
Know your concrete volume already? Enter it here to instantly estimate how many cement bags, how much sand and aggregate you need.
Concrete Mix Ratios Reference Table — M10 to M30 (2026)
Standard nominal mix ratios used in Pakistan and internationally for different structural applications.
- Grade: M10; Mix Ratio (C:S:A): 1 : 3 : 6; fck (MPa): 10; Cement (bags/m³): 4.4; Sand (m³/m³): 0.46; Agg (m³/m³): 0.92; Typical Use in Pakistan: Lean blinding layer, road base, non-structural fill
- Grade: M15; Mix Ratio (C:S:A): 1 : 2 : 4; fck (MPa): 15; Cement (bags/m³): 5.8; Sand (m³/m³): 0.44; Agg (m³/m³): 0.88; Typical Use in Pakistan: Ground slabs, pathways, plain concrete footings, mass concrete
- Grade: M20; Mix Ratio (C:S:A): 1 : 1.5 : 3; fck (MPa): 20; Cement (bags/m³): 7.6; Sand (m³/m³): 0.42; Agg (m³/m³): 0.84; Typical Use in Pakistan: Slabs, beams, columns, footings — general structural use
- Grade: M25; Mix Ratio (C:S:A): 1 : 1 : 2; fck (MPa): 25; Cement (bags/m³): 10.2; Sand (m³/m³): 0.40; Agg (m³/m³): 0.80; Typical Use in Pakistan: Heavy-loaded columns, transfer slabs, bridge decks
- Grade: M30; Mix Ratio (C:S:A): 1 : 0.75 : 1.5; fck (MPa): 30; Cement (bags/m³): 13.4; Sand (m³/m³): 0.36; Agg (m³/m³): 0.72; Typical Use in Pakistan: Pre-stressed concrete, marine structures, high-rise cores
Concrete Volume & Material Estimate Formulas
Slab / Raft Volume
V = L × W × T
Where L = Length (m), W = Width (m), T = Thickness (m). Convert thickness from mm to m before multiplying. For multiple slabs: multiply result by number of slabs.
Circular Column Volume
V = π × (D/2)² × H
Where D = Diameter (m), H = Height (m), π = 3.14159. Convert diameter from mm to m. Example: 300 mm dia × 3.0 m height = 0.212 m³.
Dry Volume Factor
V_dry = V_wet × 1.54
Dry materials occupy 54% more volume than the finished wet concrete due to voids and compaction. All material quantity estimates use the dry volume. This is the most important factor in concrete material estimation.
Cement Bags from Volume
Bags = (C_parts ÷ Total_parts) × V_dry ÷ 0.0347
Where 0.0347 m³ = volume of 1 bag of cement (50 kg). For M20 (1:1.5:3): cement part = 1, total = 5.5. Each bag weighs 50 kg. Always round up to nearest whole bag.
Sand Volume
V_sand = (S_parts ÷ Total) × V_dry
For M20 (1:1.5:3): sand volume = (1.5 ÷ 5.5) × dry volume. Sand density approximately 1,600 kg/m³ for weight conversion. Add wastage percentage after estimating base quantity.
Aggregate Volume
V_agg = (A_parts ÷ Total) × V_dry
For M20 (1:1.5:3): aggregate volume = (3 ÷ 5.5) × dry volume. Crushed stone density approximately 1,600 kg/m³. For coarse aggregate (20 mm nominal size) in Pakistan, density = 1,560–1,680 kg/m³ depending on source.
Pro Tips for Accurate Concrete Estimation
Always Add 5–10% Wastage
Concrete wastage on site is unavoidable due to spillage, over-pour in formwork, and uneven surfaces. Never order the exact estimated volume — add minimum 5% and up to 15% for difficult pours or remote locations in Pakistan.
Order Cement in Full Bags
Always round up cement bags to the nearest whole number. Partial bags deteriorate rapidly after opening. In Pakistan, a 50 kg bag = 0.0347 m³ of cement. Store bags on pallets off the ground and use within 3 months.
Deduct Rebar Volume for Large Elements
For heavily reinforced columns and beams, deduct 2–4% of gross volume for steel reinforcement. For lightly reinforced slabs (0.15–0.25% steel), deduction is negligible and is typically ignored in material ordering.
Use M25 or Above for Columns
Pakistan building practice typically specifies M20 as minimum for slabs but M25 for columns — especially in seismic zones. BCP 2021 requires fck ≥ 20 MPa (cylinder) = approximately M25 cube for all Special Structural Systems in seismic regions.
Provide 75 mm Lean Concrete Blinding
Before placing footing concrete, lay a 75 mm M10 blinding layer. This protects the main concrete from ground contamination and provides a clean working surface for reinforcement placement. Estimate blinding volume separately using the Footing guide.
Hot-Weather Concreting in Pakistan
In Pakistan summers (April–September), concrete temperature at placement must not exceed 35°C. Use chilled water or ice. Add a Type B retarding admixture (per ASTM C494 or BS EN 934-2). Plan pours for early morning or evening. Cure immediately after finishing using wet hessian.
Verify Ready-Mix Delivery Tickets
Each ready-mix truck delivery note (ASTM C94) must state: mix design ID, W/C ratio, cement content, batch time, and drum revolutions. In Pakistan, always verify the delivery note matches your specified grade before allowing discharge. Reject any load exceeding 90 minutes after batching or 300 drum revolutions.
Take Cube Samples for QC
Per BS EN 206 or ASTM C39, take 150 mm cube or 150×300 mm cylinder samples every 50 m³ or once per pour (whichever gives more samples). Test 2 cubes at 7 days and 2 at 28 days. 28-day cube strength must meet fcu ≥ fck + 4 MPa per BS EN 206 conformity criteria.