Volume: -
Volume: -
25kg Bags Needed: -
40kg Bags Needed: -
Ready-Mix Order: -
Concrete Calculator
Calculate how much concrete you need for your project. Get results in cubic meters and number of bags.
How to Calculate Concrete
Concrete volume is calculated by multiplying the dimensions of your project:
- Rectangular Slab: Length × Width × Thickness
- Circular Slab: π × Radius² × Thickness
- Column: Length × Width × Height
The calculator adds 10% for waste when calculating bag quantities.
Example
A patio slab 3m × 3m × 10cm:
- Volume: 0.9 m³
- 25kg bags needed: ~83 bags (with waste)
- Ready-mix order: 1.0 m³
FAQ
- How much does a bag of concrete cover?
- A 25kg bag covers approximately 0.012 cubic meters. A 40kg bag covers about 0.019 cubic meters. The exact coverage depends on the mix ratio.
- Should I order extra concrete?
- Yes, always order 5-10% extra for waste, spillage, and uneven surfaces. It's better to have too much than to run out mid-pour.
- When should I use ready-mix vs bags?
- Use bags for small projects under 0.5 cubic meters. For larger projects, ready-mix concrete is more economical and ensures consistent quality.