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Concrete Wall Calculator

A concrete wall calculator works out the ready-mix for a poured wall — a foundation wall, a stem wall or a low retaining stem. Enter the length, the height and the thickness, and it returns cubic yards and metres plus a bag count, with 10% waste added.

Your measurements

Result

Wall thickness is usually 6, 8 or 10 inches depending on what it retains or carries. Measure the full length of the wall and its finished height above the footing.

How it is calculated

Wall volume is length × height × thickness, with the thickness converted from inches to feet. We convert to cubic yards or metres and bag counts and add a 10% allowance for form bulge, spillage and over-fill at the top.

Steps

Measure the wall length in feet.
Enter the finished height in feet.
Enter the thickness in inches — 8 inches is a common foundation thickness.
Read the cubic-yard total for your ready-mix order.
Order to the 10%-waste line so a slightly bowed form does not leave you short.

Worked example

A 20 ft wall, 4 ft high and 8 inches thick is 20 × 4 × 0.67 = about 53 cubic feet, or just under 2 cubic yards before waste.

Common questions

How thick should a concrete wall be?

Foundation and stem walls are commonly 6–10 inches; the exact figure comes from the load and your local code.

How is a wall different from a footing?

The footing is the wide strip the wall sits on. Size the footing and the wall separately, then add them for the total pour.

Do poured walls need rebar?

Yes — horizontal and vertical rebar to a schedule set by the engineer. This tool sizes the concrete, not the steel.

Can I pour a wall with bags?

Only a very short, low one. A normal foundation wall is several yards and needs a ready-mix delivery, often with a pump.