Overview
What is the Concrete Wall Calculator?
A wall calculator estimates the concrete inside vertical forms. Length follows the wall run, height is the pour height, and thickness is the wall width. Openings, steps in the footing, and battered faces may still need a sketch take-off on top of this rectangle.
A wall pour is length times height times thickness, not the slab formula. Enter those three dimensions to get cubic yards for stem walls, garden walls, and basement pours, then add waste for pump lines and honeycombing. Use the result to brief the plant on volume, not just how long the wall is.
Workflow
How does it work?
Each dimension converts to metres. Volume is length × height × thickness, times quantity for repeated identical walls. Waste multiplies that raw volume. Bag counts and weight follow the same yields and density used on the main concrete calculator.
Switch units if needed, then set thickness in inches or millimetres for typical 8-inch walls.
Choose Wall so height is used instead of slab thickness as the vertical dimension.
Enter formed length, pour height, and wall thickness from the drawings.
Deduct large openings separately if they are big enough to change the order; small block-outs are often left in the waste factor.
Add waste for pump lines and imperfect forms — 10% is a common site starting point.
Read cubic yards and bag counts, then confirm mix grade with the specifier.
Math
Formula
Volume = length × height × thickness × quantity × (1 + waste%)
A formed wall is a vertical box. Height is the pour face, not footing depth. Thickness is the distance between forms. Convert mixed units before multiplying. Waste scales the result; bags and weight are logistics estimates from that volume.
Inputs
Step-by-step variables
L
Length
Horizontal run of the wall along the forms.
H
Height
Vertical pour height from the bottom of the wall pour to the top of concrete.
T
Thickness
Distance between form faces. Eight inches is common for residential stem walls.
Practice
Step-by-step examples
30 ft stem wall, 8 ft high, 8 in thick
Length 30 ft, height 8 ft, thickness 8 in (0.667 ft), 10% waste. Raw volume is 30 × 8 × 0.667 = 160 ft³, or 5.93 yd³.
About 6.52 yd³ with 10% waste (≈ 4.98 m³). That is a ready-mix pour, not a bag job.
Garden wall 12 m × 1.2 m × 200 mm
Metric wall: 12 m long, 1.2 m high, 200 mm thick, 8% waste. Raw volume is 12 × 1.2 × 0.2 = 2.88 m³.
About 3.11 m³ after 8% waste (≈ 4.07 yd³). Switch the form to Metric and set thickness in millimetres.
Where it helps
Use cases
- Stem walls on top of strip footings
- Garden and retaining wall pours (volume only)
- Basement wall takeoffs before a pump truck is booked
Avoid these
Common mistakes
- Using slab thickness as wall height.
- Forgetting that 8 inches is 0.667 feet, not 8 feet.
- Ignoring that a retaining wall also needs geotech and drainage design beyond volume.
Buying & planning
Tips
- Measure formed length after corners; inside and outside faces differ.
- Keep the footing takeoff on its own page so wall and footing are not merged.
- Ask the plant about slump and maximum aggregate for a narrow wall pour.
Need the bigger picture? Read our calculator disclaimer and accuracy policy.