Plan accurate concrete batches for slabs, footings, columns, and repairs today fast. Estimate cement bags, sand, aggregate, and water from site dimensions quickly clearly.
| Scenario | Inputs | Outputs (approx.) |
|---|---|---|
| Slab pour | L=6 m, W=4 m, D=0.12 m, waste=5%, ratio=1:2:4 | Wet=2.88 m³, Dry≈4.66 m³, Bags≈67 (50 kg), Water≈2410 L |
| Footing | Volume=1.20 m³, waste=7%, ratio=1:1.5:3 | Dry≈1.98 m³, Bags≈41 (50 kg), Water≈1470 L |
| Repair work | Volume=15 ft³, waste=5%, ratio=1:2:4 | Wet≈0.42 m³, Dry≈0.68 m³, Bags≈10 (50 kg), Water≈350 L |
Accurate batching today helps deliver stronger, safer concrete pours.
Batch planning reduces delays, cold joints, and costly over-ordering. For small pours, a few missing bags can stop placement and compromise finishing time. For larger pours, accurate quantities help coordinate mixers, pumps, and labor so concrete arrives and is placed within workable slump and setting windows. It also improves cost control by matching purchases to practical site production rates and storage limits.
Volume starts with geometry. Slabs use length × width × thickness, footings use length × width × depth, and columns use cross‑sectional area × height. If you already know volume from drawings, enter it directly. Convert feet to meters carefully to keep procurement aligned.
Waste covers spill, rebound, uneven subgrade, form leakage, and cleanup losses. Typical allowances range from 3–10% depending on access and placement method. Tight forms and pump placement often reduce waste, while hand mixing, long wheelbarrow runs, or irregular trenches usually increase it.
Concrete ingredients are measured as dry volumes but placed as wet concrete. The dry factor (often around 1.50–1.60) accounts for voids between aggregates and bulking effects. Use a higher factor when aggregates are poorly graded or handling causes segregation and extra void space.
Nominal ratios such as 1:2:4 or 1:1.5:3 are common for general work, but structural elements should follow project specifications for strength, durability, and exposure. Changing ratio shifts paste content, workability, and finishing response. Keep consistency across batches for uniform curing behavior.
This calculator converts ingredient volumes into approximate masses using typical bulk densities. Cement is often near 1440 kg/m³, sand near 1600 kg/m³, and coarse aggregate near 1500 kg/m³. If your supplier provides verified densities, enter them to tighten ordering accuracy.
The water estimate is based on the selected water–cement ratio (w/c). Lower w/c generally improves strength and reduces permeability, but too little water can reduce workability and consolidation quality. Consider moisture in sand, admixtures, and slump targets before final water dosing on site.
Before buying materials, confirm rebar cover, form dimensions, and thickness tolerances. Verify that the mix ratio matches the intended application, and review curing plans for temperature and wind. Document final numbers with the CSV or PDF export to support audits and daily reports.
It adjusts wet concrete volume to the larger dry ingredient volume needed to fill voids and account for bulking. Many field estimates use 1.54, but local materials and handling can justify different values.
Use 3–5% for clean forms and easy access. Use 7–10% for irregular trenches, hand mixing, or difficult transport. If rework is likely, add extra for contingency.
Presets are general guidance. Structural concrete should follow an engineered mix design that meets strength, durability, and exposure requirements. Use the calculator for planning quantities, then align with specifications.
Metric provides consistent mass and volume relationships for purchasing and reporting. If you enter feet, the calculator converts internally to metric, then exports uniform units for easier comparison across jobs.
Yes. Update bag size and material densities to match local packaging and supplier data. Using supplier values improves accuracy, especially when sand moisture and aggregate grading differ from typical assumptions.
No. The water estimate assumes dry ingredients. If sand is damp, reduce added water accordingly. Field adjustments should be based on measured moisture, slump checks, and finishing performance.
No. It supports batching and ordering decisions. Certified designs and trial mixes are still required for critical structural elements, durability classes, and compliance with local standards.
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.