About the Concrete Mix Ratio Calculator
Cement, sand, aggregate and water for any mix ratio and volume, by weight and by bag.
Also known as: mix ratio calculator, cement sand aggregate ratio, m20 mix design, concrete proportions.
How to use this calculator
- Enter wet concrete volume, mix ratio, cement bag size, water / cement ratio 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
dry volume = wet × 1.54, then split by the ratio parts
Worked example
Using the values pre-filled in the calculator above:
- Wet concrete volume = 1 m³
- Mix ratio: 1 : 1.5 : 3 (M20) — 20 MPa — slabs and footings
- Cement bag size = 50 kg
- Water / cement ratio = 0.5
the calculator returns:
- Cement: 403.2 kg
- Cement bags: 9
- Sand: 0.42 m³
- Sand by weight: 672 kg