Concrete Calculator

How to use the concrete calculator

This calculator helps you quickly estimate concrete volume (m³) and required materials for mixing: cement, sand, gravel and water. It’s useful for planning purchases, budgeting, and checking quantities for different structural elements (slabs, walls, columns, etc.).

Step-by-step

1) Choose a “Shape” — the calculator applies the correct volume formula.

2) Enter dimensions in meters — length, width, height/thickness, or diameter for round columns.

3) Pick a mix ratio (cement:sand:gravel) — this splits the dry volume across materials.

4) Check the “Dry volume factor” (often ~1.54) — accounts for voids and mixing losses.

5) Set workability — this is W/C (water/cement). Water (liters) is computed automatically.

6) Click “Calculate” — you’ll get volume, KPI results, chart and a materials table.

What does L×W×H / T mean?

These letters are shorthand used in the shape labels:

• L — length (m): the longest horizontal dimension.
• W — width (m): the other horizontal dimension.
• H — height (m): vertical dimension (beams, walls, columns).
• T — thickness (m): for “flat” elements (slabs, pads).
• D — diameter (m): for round columns only.

For example, L×W×T = length × width × thickness, and L×W×H = length × width × height.

What does “Shape” mean in this calculator?

Slab (L×W×T) — floors, pavements, roof slabs, foundation slabs.

Footing/Foundation pad (L×W×T) — base under walls/columns to spread load.

Beam (L×W×H) — horizontal load-bearing element between supports.

Wall (L×H×T) — vertical structures (basements, retaining walls).

Column — rectangular (L×W×H) — vertical member with rectangular cross-section.

Column — round (D×H) — cylindrical column (volume = π × r² × height).

How the calculator estimates materials

First, it calculates the wet volume from your dimensions. Then it multiplies by the dry volume factor to estimate dry ingredients. Next, the dry volume is split into cement, sand and gravel according to the selected mix ratio.

Water is derived from W/C (water/cement): water (kg) ≈ cement (kg) × W/C, and 1 kg of water ≈ 1 liter.

Material cost block

If you want a budget estimate, open “Material cost” under the materials table and enter your prices (cement per bag, sand/gravel per m³). The calculator will show total cost and cost per 1 m³ of concrete.