How many cement bags are needed per m³ of concrete?

For standard concrete (250 kg/m³ mix), you need 5 bags of 50 kg per m³. For structural concrete (300 kg/m³), use 6 bags. This calculator uses the typical dosage for each element type.

Why should I add a wastage percentage?

On-site losses from spillage, unusable mixes and level corrections always occur. Adding 5–10 % to your final order ensures you don't run short of material.

What is the difference between mass concrete and reinforced concrete?

Mass concrete has no steel reinforcement and is used for low-load foundations. Reinforced concrete includes steel bars that provide tensile strength, making it suitable for slabs, columns and beams.

Isolated Footing Calculator

Last updated: 2026-05-09

Use the Isolated Footing Calculator to get instant, accurate results. Enter your values below.

Inputs

Dimensions

Footing length (m) (m)

Footing width (m) (m)

Footing depth (m) (m)

Quantities & Type

Number of footings

Wastage Allowance (%)

Result

Enter values and press Calculate

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Common Sizes — Click to Fill

Footing length (m) (m)	Footing width (m) (m)	Footing depth (m) (m)	Number of footings (ud)
0.8 m	0.8 m	0.4 m	4 ud
1 m	1 m	0.5 m	6 ud
1.2 m	1.2 m	0.6 m	8 ud
1.5 m	1.5 m	0.6 m	10 ud

Popular combinations

Footing 1.0×1.0m – 2 Footings Concrete Footing 1.0×1.5m – 6 Footings Concrete Footing 1.2×1.2m – 2 Footings Concrete Footing 1.5×1.5m – 2 Footings Concrete Footing 1.8×1.0m – 6 Footings Concrete Footing 1.8×1.8m – 2 Footings Concrete Footing 2.0×1.2m – 6 Footings Concrete Footing 2.0×1.8m – 10 Footings Concrete

What is an Isolated Footing?

An isolated footing (pad footing) is a reinforced concrete foundation that supports a single column. It spreads the column load over a wider area of soil. Common in residential and commercial buildings where soil has good bearing capacity and column spacing is regular.

Concrete Volume Calculation

Volume = Length × Width × Depth × Number of footings

The calculator accounts for both concrete volume and formwork area. Standard isolated footings in Spain range from 1.0m to 2.5m per side depending on column load and soil capacity.

Worked Example

4 footings of 1.5m × 1.5m × 0.50m:

Volume per footing = 1.5 × 1.5 × 0.50 = 1.125 m³
Total concrete = 1.125 × 4 = 4.5 m³
Cement = 4.5 × 7 = 32 bags (50 kg)
Steel = 4.5 × 100 kg/m³ = 450 kg
Formwork = 4 × perimeter × depth = 4 × 6 × 0.50 = 12 m²

Common Mistakes

Not excavating to frost-free depth (minimum 50-80cm in most climates)
Insufficient footing area for soil bearing capacity
Missing reinforcement in the tension zone (bottom of footing)
Not compacting the subgrade before pouring concrete

Standards

Calculated per EN 1992-1-1 / EN 1997-1 (Eurocode 2 & 7).

Written and reviewed by the CalcToWork editorial team. Last updated: 2026-05-09.