Enter the dimensions of your slab, the cement dosage (kg/m³) and the bag weight. The calculator will estimate the concrete volume and number of bags needed.
About this concrete volume and cement bags calculator
This concrete calculator helps you estimate the volume of concrete needed for a rectangular slab using its length, width, and thickness. The volume is expressed in cubic meters (m³), which is the standard unit used by ready-mix suppliers and on construction plans.
It also estimates the amount of cement required based on a chosen cement dosage (kg of cement per m³ of concrete), then converts that total into an approximate number of cement bags depending on the bag weight (for example 25 kg, 35 kg, or 40 kg). This is useful when preparing a small slab, footing, shed base, walkway, or similar work.
The calculation is simplified and does not include aggregates, water ratio, reinforcement, site losses, or specific standards for different concrete classes. In practice, it is common to add a safety margin (for example 5–10%) to account for waste, uneven thickness, and handling.
All calculations are performed locally in your browser (client-side). No form data is uploaded or stored.