Concrete Calculator
Compute cement, sand, gravel and water for any volume of concrete. Ready-made mixes (PINI/ABNT) and instant calculation.
Concrete data
Recalculates automatically as you type
Important. Values follow practical coefficients from PINI/ABNT NBR 12655 and TCPO reference tables. Always confirm the mix with your cement supplier and/or responsible engineer.
Cement
8
bags · 50 kg
Sand
0.58
m³
Gravel
0.86
m³
Water
221
liters
Material summary
| Item | Quantity | Unit |
|---|---|---|
| Gross volume | 1.00 | m³ |
| Volume with waste | 1.05 | m³ |
| Cement | 8 bags · 368 kg | 50 kg/bag |
| Medium sand | 0.58 | m³ |
| Coarse aggregate | 0.86 | m³ |
| Water (w/c ≈ 0.6) | 221 | liters |
| Mix used | 1 : 3 : 3 | — |
Frequently Asked Questions
For structural concrete (beams, slabs, columns) it's best to follow a design with fck specified by an engineer. As a practical reference: 1:3:3 delivers ~20 MPa, 1:2.5:3 ~25 MPa, 1:3:4 is typical for floors and screeds, and 1:4:6 for lean concrete / bedding.
On site there's always waste from leftover mix, spillage, formwork adjustments and thickness variation. 5% is the practical default; for small jobs or irregular shapes, consider 10%.
Depends on the mix. With 1:3:3 (structural), a 50 kg bag yields roughly 0.14 m³ of concrete. With lean mixes (1:4:6) the yield rises to ~0.25 m³ per bag.
It's a practical approximation. NBR 6118 and NBR 12655 set ratios by environmental aggressiveness class — generally between 0.45 and 0.65. The lower the ratio, the higher the strength and durability.
No. For ready-mix you buy by the m³ and the supplier delivers per the fck. This calculator is for site-mixed concrete (mixer or hand-mixed).