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Concrete Wall Calculator

Volume for a poured concrete wall, stem wall or retaining wall of even thickness. Enter length and height in feet and thickness in inches.

What are you pouring?
Units

Wall

Subtract large openings such as windows and doors separately.

Bag size
Add your prices (optional)

Use your supplier's prices. We don't show average prices because they vary too much by area.

Concrete needed

2.17 cubic yards

58.7 ft³ · 1.66 m³ · includes 10% extra

You need about 2.17 cubic yards of concrete, or 98 bags of 80 lb mix.

Bags of premix

  • 19640 lb bags
  • 15750 lb bags
  • 13160 lb bags
  • 9880 lb bags
  • Before extra1.98 yd³ (53.3 ft³)
  • Weight of bags7,840 lb
  • Ready-mix costAdd a price per yd³
  • Bagged costAdd a price per bag

One 80 lb bag makes about 0.60 ft³ (manufacturer's published yield). Bags are rounded up.

At 2.17 yd³ that is 98 × 80 lb bags (7,840 lb) to mix. Most people order ready-mix at this size; ask suppliers for their minimum load and any short-load fee.

Estimate only, not a quote or engineering advice. Disclaimer

How wall volume is calculated

Cubic yards = Length (ft) × Height (ft) × Thickness (in) ÷ 12 ÷ 27

Example: a wall 30 ft long, 8 ft high and 8 inches thick is 30 × 8 × 0.667 = 160 ft³, or 5.93 yd³. With 10% extra, order about 6.5 yd³.

Concrete per 10 square feet of wall face

Per 10 sq ft of wall (length × height), before waste
Thicknessft³yd³Sq ft of wall per yd³
6 in5.000.18554
8 in6.670.24741
10 in8.330.30932
12 in10.000.37027

Windows, doors and openings

Work out each opening as its own small wall (width × height × wall thickness) and subtract it. For a stepped or tapered wall, split it into sections of even height and add them.

The wall's footing is separate: run it in the footing calculator and add the two. Walls are almost always poured from a truck, often with a pump, so read ready-mix vs bags before you order.

Frequently asked questions

How many yards of concrete for an 8-inch wall?

An 8-inch wall uses 0.667 ft³ per square foot of face, so one cubic yard builds about 40.5 sq ft of wall. A 30 ft × 8 ft wall (240 sq ft) needs 5.93 yd³ before waste.

How do I account for a sloped top or a step?

Split the wall into sections that each have a single height, calculate each one, and add them. For a wall that slopes evenly, the average of the two end heights gives the same volume.

Can I pour a wall with bagged concrete?

Short, low walls, yes. Larger walls are usually poured in one go from ready-mix trucks so there are no cold joints between batches. Ask a contractor before pouring a wall that retains soil or carries a building.

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