Inputs
Results
Enter inputs and click Calculate.
| Item | Quantity | Units |
|---|
Formulas used
- Wet volume: for dimensions → L × W × T. For direct volume → user value.
- Adjusted dry volume: Wet × Dry factor × (1 + Waste%).
- Mix parts: total parts = C + S [+ A].
- Cement volume: Dry × (C / total).
- Cement mass: Cement volume × density.
- Cement bags: Cement mass / bag size.
- Sand volume: Dry × (S / total).
- Aggregate volume: Dry × (A / total) (concrete only).
- Water: W/C × cement mass (L if metric, gal if imperial).
Defaults: density 1440 kg/m³ (or 94 lb/ft³), dry factor 1.54 for concrete and 1.33 for plaster/mortar.
How to use this calculator
- Select your unit system and application type.
- Choose how to provide volume: either enter slab/wall dimensions or supply a direct wet volume.
- Pick a mix preset or enter custom parts for cement, sand, and (for concrete) aggregate.
- Adjust dry factor, waste, density, bag size, and water–cement ratio if needed.
- Press Calculate to see cement bags, volumes of sand and aggregate, and water requirements.
- Use Download Results CSV or Download PDF to export.
Example data
| Application | Unit | Length | Width | Thickness | Wet Vol | Mix | Dry Factor | Waste % |
|---|---|---|---|---|---|---|---|---|
| Concrete | metric | 4 m | 3 m | 0.15 m | 1.80 m³ | 1:2:4 | 1.54 | 5 |
| Plaster | metric | 5 m | 2.8 m | 0.015 m | 0.21 m³ | 1:4 | 1.33 | 5 |
| Concrete | imperial | 12 ft | 10 ft | 6 in | 50.0 ft³ | 1:1.5:3 | 1.54 | 5 |
Example rows illustrate typical inputs. Use the calculator above for live results.
FAQs
For concrete a common assumption is 1.54. For plaster or masonry mortar 1.33 is often used. Adjust if your material handling or site conditions differ.
You can set any bag size. Defaults are 50 kg for metric and 94 lb for imperial. The calculator derives bag count from cement mass divided by bag size.
Results are planning estimates. Real requirements depend on material moisture, compaction, aggregate gradation, and site losses. Always verify with your supplier or engineer before ordering.
Typical structural concrete uses 0.40–0.55. Lower values improve strength but reduce workability. For plaster/mortar use a workable consistency while avoiding excessive water.
Yes. Switch to Direct volume and enter the wet volume in m³ or ft³. The calculator applies dry factor and waste automatically.