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Foundation Quantity Calculator

Calculate component concrete volumes, base quantity, waste allowance, order quantity, footprint, and concrete intensity.

Slab length (m)Slab width (m)Slab thickness (m)Total footing length (m)Footing width (m)Footing depth (m)Stem wall height (m)Stem wall thickness (m)Concrete waste allowance (%)

Slab concrete volume (m3)-

Footing concrete volume (m3)-

Stem-wall concrete volume (m3)-

Base concrete quantity (m3)-

Waste allowance volume (m3)-

Concrete order quantity (m3)-

Slab footprint (m2)-

Concrete per footprint area (m3/m2)-

Decision view

Foundation section and concrete-volume composition

Foundation section and concrete-volume compositionThe engineering section identifies slab, footings, and stem walls while the volume stack reconciles base concrete, waste, and order quantity.

Exact scenario comparisonConcrete waste allowance (%) changes while all other entered assumptions remain constant.

Concrete waste allowance (%)	Slab concrete volume (m3)	Footing concrete volume (m3)	Stem-wall concrete volume (m3)	Base concrete quantity (m3)	Waste allowance volume (m3)	Concrete order quantity (m3)	Slab footprint (m2)	Concrete per footprint area (m3/m2)

How to use Foundation Quantity Calculator

Enter the slab, footing, and stem-wall dimensions from the plan.
Enter a separate waste allowance.
Verify the section diagram and component volumes.

Calculator guide

Understanding Foundation Quantity Calculator

Foundation concrete quantity is the sum of distinct slab, footing, and stem-wall prisms before waste.

Calculate slab volume All slab dimensions are already in meters.

Calculate footing volume The entered footing length represents the total continuous length.

Calculate stem-wall volume The stem wall uses the same entered total foundation length.

Add base and waste Waste is a separate visible addition to the exact geometric base.

Calculation method

How the calculation works

Calculate slab, continuous footing, and stem-wall volumes from explicit dimensions, then add a separately visible waste allowance. Multiply the explicit dimensions of each concrete component, sum base volume, then apply waste once to the total.

Detailed calculation process

Reconcile slab, footing, and stem-wall concrete

The default models a 12 m by 9 m by 0.15 m slab, 42 m of 0.6 m by 0.3 m footing, 0.6 m by 0.2 m stem walls, and 7% waste.

General formula: V_s = L_s W_s t_sV_f = L_f W_f d_fV_w = L_f h_w t_wV_base = V_s+V_f+V_wV_waste = V_base(w/100)V_order = V_base+V_wasteA_fp = L_s W_sq = V_order/A_fp Each structural component is treated as a rectangular prism. Waste is applied only after the three component volumes are summed, preventing double counting.

What each symbol means

L_s, W_s, t_s Slab length, width, and thickness (m).

L_f, W_f, d_f Total footing length, width, and depth (m).

h_w, t_w Stem-wall height and thickness (m).

V_s, V_f, V_w Slab, footing, and stem-wall volumes (m³).

w Concrete waste allowance (%).

V_base, V_waste, V_order Base, waste, and order volumes (m³).

A_fp Slab footprint area (m²).

q Order volume per footprint area (m³/m²).

Worked substitution with the default inputs

1. Calculate slab volume V_s = 12(9)(0.15)V_s = 16.2 m^3 All slab dimensions are already in meters.

2. Calculate footing volume V_f = 42(0.6)(0.3)V_f = 7.56 m^3 The entered footing length represents the total continuous length.

3. Calculate stem-wall volume V_w = 42(0.6)(0.2)V_w = 5.04 m^3 The stem wall uses the same entered total foundation length.

4. Add base and waste V_base = 16.2+7.56+5.04 = 28.8 m^3V_waste = 28.8(0.07) = 2.016 m^3 Waste is a separate visible addition to the exact geometric base.

5. Reconcile order and footprint V_order = 28.8+2.016 = 30.816 m^3A_fp = 12(9) = 108 m^2q = 30.816/108 = 0.285333 m^3/m^2 The component stack plus waste closes exactly to the order quantity.

The default geometric base is 28.8 m³; 7% waste adds 2.016 m³ for a 30.816 m³ order quantity.

Purpose-built visual

Foundation section and volume stack

An engineering section identifies slab, footing, and stem wall while a component stack reconciles their volumes and waste.

Live The chart is regenerated from current inputs.

Units Every axis, marker, and endpoint retains its stated unit.

Check The chart reconciles to the displayed calculation.

Worked situations

Practical examples

The default models a 12 m by 9 m by 0.15 m slab, 42 m of 0.6 m by 0.3 m footing, 0.6 m by 0.2 m stem walls, and 7% waste.
The default geometric base is 28.8 m³; 7% waste adds 2.016 m³ for a 30.816 m³ order quantity.

Better inputs

Useful tips

Change one input at a time and confirm both the result and visual move.
Keep the units stated beside every field.
Retain intermediate precision and round only the reported result.

Before relying on the result

Limitations and common mistakes

Steps, piers, grade beams, openings, and thickened regions are excluded.
Over-excavation, tolerances, and reinforcement displacement are not modeled.
Local plans and codes govern actual quantities.

Reference

Key terms

Base quantity: Exact modeled component volume before waste.
Stem wall: Foundation wall rising from the footing.
Waste allowance: Entered percentage added once to base volume.

Important note

Calculated from the entered measurements and stated coverage or quantity rules. Confirm field dimensions, waste, product requirements, structural conditions, and local codes before purchasing or building.

Frequently asked questions

Is waste applied to each component?

The model applies it once to their sum.

Does footing length include every run?

Yes; enter the complete total.

Are openings subtracted?

Only if the entered dimensions already account for them.

Is this a structural design?

No.