How thick should a concrete slab be?

Footpaths and patios: 75–100 mm (0.075–0.1 m). Driveways for cars: 100–125 mm. Driveways for heavy vehicles: 150 mm. Structural foundations: 200 mm+.

How many bags of concrete make 1 m³?

Approximately 108 × 20 kg bags (or 54 × 40 kg bags) mix to make 1 m³ of concrete. Pre-mixed concrete is more economical for volumes over 0.5 m³.

How heavy is 1 m³ of concrete?

Standard concrete weighs approximately 2,400 kg (2.4 tonnes) per cubic metre. This is important when planning deliveries and structural loads.

Concrete Calculator — How Much Concrete Do I Need?

The Concrete Calculator estimates how many cubic metres of concrete you need for a rectangular slab or footing. Ordering the right amount prevents costly over-ordering and project delays from running short. The calculator adds a recommended 10% extra to account for spillage and uneven ground.

Length(m)

Width(m)

Depth / Thickness(m)

Frequently Asked Questions

Volume = Length × Width × Depth. For example, a 5m × 3m slab at 10 cm (0.1 m) deep = 5 × 3 × 0.1 = 1.5 m³ (1.65 m³ with 10% extra).

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