DIY & materials
Concrete Volume and Bag Calculator
Estimate wet concrete and bag counts using stated product yields. This free concrete volume and bag calculator shows the calculation and its assumptions so you can compare your own figures.
Your results
Estimate wet concrete and bag counts using stated product yields.
Calculated outcomes
- Wet Concrete Weight Kg
- 4,800 kg
- Dry Volume M3
- 3.08 m³
- Estimated Cement Kg
- 633.6 kg
- Estimated Sand Kg
- 1,408 kg
- Estimated Aggregate Kg
- 2,640 kg
- Cement25 Kg Bags
- 26
- Sand25 Kg Bags
- 57
- Aggregate25 Kg Bags
- 106
Assumptions and estimates
- Ready-mix bags use the entered manufacturer yield; wet concrete weight cannot determine dry bag quantity. Separate site-mix estimates use a loose-volume ratio, dry-volume factor 1.54 and editable bulk densities (cement 1440, sand 1600, aggregate 1500 kg/m³). These planning assumptions do not specify certified strength, water/cement ratio, compaction or structural suitability.
- Method: Wet volume is length × width × depth. Ready-mix bags use manufacturer volume yield; separate constituent estimates use an explicit dry-volume mix ratio.
- Wet concrete mass cannot be divided by 25 kg to obtain dry bag counts. Mix ratios and loose bulk densities are estimates, not a structural concrete specification.
Useful next steps
- Use Compare options to test an alternative side by side.
- Copy, print or download a record of this calculation when you need one.
Reports open your email app addressed to s@s1.ie with the public page address only. Your inputs are never added.
How the concrete & dry materials calculation works
Wet volume is length × width × depth. Ready-mix bags use manufacturer volume yield; separate constituent estimates use an explicit dry-volume mix ratio.
Wet concrete mass cannot be divided by 25 kg to obtain dry bag counts. Mix ratios and loose bulk densities are estimates, not a structural concrete specification.
Using this calculator
- Enter your own figures in the labelled inputs. Keep the currencies, units and time periods consistent.
- Choose any applicable rate profile, pattern or assumption shown for this tool. Open additional inputs when relevant.
- Review volume m3 and ready mix25 kg bags, then read the stated assumptions and eligibility conditions before using the result.
Worked example
This is a static example using illustrative inputs, not facts about you or today’s date. The displayed eligibility selections and assumptions apply only to this example.
See example inputs
- Length (m)
- 5
- Width (m)
- 4
- Depth (m)
- 0.1
- Wet concrete density (kg/m³)
- 2400
- 25 kg ready-mix bag yield (litres)
- 12
- Loose-volume cement parts
- 1
- Loose-volume sand parts
- 2
- Loose-volume aggregate parts
- 4
- Dry-volume conversion factor
- 1.54
- Loose cement bulk density (kg/m³)
- 1440
- Loose sand bulk density (kg/m³)
- 1600
- Loose aggregate bulk density (kg/m³)
- 1500
- Volume M3
- 2 m³
- Ready Mix25 Kg Bags
- 167