Plan raft pours with precise volume insights today. Account for openings, thick edges, and waste. See daily output, trucks, and cement needs instantly here.
For daily planning, the tool uses pour hours and productivity to estimate capacity, then spreads total concrete across whole planned days.
Sample values and indicative outputs for a typical slab with thickened edges and ribs.
| Scenario | Key inputs | Key outputs |
|---|---|---|
| Metric sample |
L=20 m, W=15 m, T=350 mm Openings=6 m², Waste=5% Edge=0.6 m & +150 mm Beams=30 m, 0.3 m & +250 mm Hours=8, Rate=12 m³/hr, Truck=6 m³ |
Net with waste ≈ 117.023 m³ Planned days ≈ 2 days Daily volume ≈ 58.511 m³/day Trucks/day ≈ 10 (6 m³) |
| Imperial sample |
L=65.6 ft, W=49.2 ft, T=14 in Openings=64.6 ft², Waste=5% Edge=2.0 ft & +6 in Beams=98.4 ft, 1.0 ft & +10 in Hours=8, Rate=15.7 yd³/hr, Truck=8 yd³ |
Net with waste ≈ 153.1 yd³ Planned days ≈ 2 days Daily volume ≈ 76.6 yd³/day Trucks/day ≈ 10 (8 yd³) |
Example outputs are rounded. Use your exact project values for procurement and pour scheduling.
Gross raft volume
Gross = Length × Width × Thickness
Openings deduction
Openings = Total opening area × Thickness
Edge thickening addition
Edge add = Perimeter × Strip width × Extra thickness
Beam (rib) addition
Beam add = Total beam length × Beam width × Extra depth
Net volume with waste
Net = (Gross − Openings + Edge add + Beam add) × (1 + Waste%)
Daily capacity and planned days
Daily capacity = Productivity rate × Pour hours. Planned days = ceiling(Net ÷ Daily capacity). Daily volume = Net ÷ Planned days.
Raft foundations are typically placed in controlled stages to protect finish quality, maintain pump continuity, and coordinate reinforcement inspection. A daily volume target supports concrete ordering, labour allocation, and equipment scheduling. By estimating planned pour days from site capacity, the team can prevent late deliveries, idle crews, and cold joints caused by unplanned stoppages.
Simple length, width, and thickness provide a baseline volume, but real rafts include openings, trenches, and thickened zones. Deductions for lift pits, sleeves, and service penetrations avoid over-ordering. Edge thickening and internal ribs add volume beyond the slab, so capturing perimeter strips and beam lengths improves procurement accuracy and reduces waste.
Waste is influenced by access, pumping distance, finishing method, and rehandling. A modest allowance helps cover spillage, residual truck discharge, and trim losses. When daily targets are set, delivery can be sequenced to match placing rhythm. Truck capacity and travel constraints can be translated into expected loads per day, supporting dispatch coordination and site traffic control.
Productivity rates vary with crew size, pump output, congestion from dense steel, and vibration requirements. Pour hours should reflect actual workable time including breaks, testing, and finishing passes. Using conservative values improves schedule reliability. If the exact duration is not practical, distributing total volume across whole days provides a workable daily target for ordering and supervision.
Example (metric): L=20 m, W=15 m, thickness=350 mm, openings=6 m², edge strip=0.6 m with +150 mm, beams=30 m at 0.3 m with +250 mm, waste=5%, hours=8, rate=12 m³/hr, truck=6 m³. This produces a net with waste near 117.023 m³, planned as 2 days, about 58.511 m³/day, roughly 10 trucks/day. Adjust openings and thickening first, then refine rate and hours to match actual site constraints.
Placing plans are usually organized in full working days. Rounding up protects against shortfalls and makes ordering simpler, while the daily target stays practical for crews and deliveries.
Add all cutout areas such as lift pits, sumps, trenches, and large penetrations. Use drawings to calculate each rectangle or circle, then sum them into one total opening area.
It is the added depth beyond the slab thickness within a perimeter strip. If the edge is 500 mm thick and the slab is 350 mm, the extra thickness is 150 mm.
Include ribs or grade beams that are monolithic with the raft and deeper than the slab. Enter the total beam length, beam width, and the extra depth beyond the slab thickness.
Well-controlled pours may use 3–5%. Congested reinforcement, long pumping lines, or difficult access can push waste higher. Review past pours and adopt a conservative allowance.
Start from pump capacity and crew placing speed, then reduce for testing, finishing, and congestion. If uncertain, use a lower rate and compare with actual daily volumes achieved on similar work.
They are indicators based on cement content and bag size inputs. Mix designs vary by strength, aggregates, and admixtures, so confirm final quantities with your approved design and supplier.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.