About the Cement Calculator
Cement bags needed for concrete, mortar or plaster from the volume and mix ratio.
Also known as: how many bags of cement, cement bag calculator, cement quantity, bags of cement per m3.
How to use this calculator
- Enter what for?, volume, bag size, price per bag and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
cement = dry volume × (cement parts ÷ total parts) × 1440 kg/m³
Worked example
Using the values pre-filled in the calculator above:
- What for?: Concrete
- Volume = 1 m³
- Mix ratio: 1 : 1.5 : 3 (M20) — 20 MPa — slabs and footings
- Bag size = 50 kg
- Price per bag = 8
the calculator returns:
- Cement bags: 9
- Cement by weight: 403.2 kg
- Sand: 0.42 m³
- Aggregate: 0.84 m³