Concrete Footing Calculator

What this footing calculator covers

Rectangular footing estimating is usually straightforward once the footing length, width, and depth are known. The volume of one footing can be solved from those dimensions, scaled by the number of identical footings, and then increased by a waste allowance so the order quantity is less likely to come up short on site.

That makes a footing concrete calculator useful for strip footings, pad footings, and similar rectangular pours where the geometry is regular. The result is shown both as a raw volume and as a more practical order figure with bag comparisons and a ready-mix cue.

Core footing volume formulas

The calculation first converts the entered dimensions into a common unit, solves the rectangular footing volume, multiplies by footing count, and then applies the waste allowance. It then converts that total into cubic yards or cubic metres and into indicative bag counts using common bag yields for planning.

How to use the footing concrete estimate

Use the total order volume when comparing supplier quotes and use the per-footing number to check whether the footing detail looks sensible against the drawing. The bag counts are useful for small jobs and remote sites, while the ready-mix cue becomes more relevant as the total footing quantity gets larger.

For example, six footings that each measure 4 feet by 2 feet by 12 inches require just under 2 cubic yards of concrete after a 10% waste allowance. At that size, it is usually worth comparing the cost and labour of bagged mixing against a ready-mix delivery.

What this result does not cover

This page estimates concrete quantity only. It does not include stepped footings, sloped excavation, thickened edges, blinding layers, rebar displacement, or variations between footing sizes in the same batch. It assumes each footing in the calculation shares the same plan dimensions and depth.

Use the estimate as a procurement planning aid, then confirm the actual pour size and delivery basis from the foundation detail, engineer notes, and supplier guidance before you order material.