Concrete Wall Calculator — ft to cu yd, bags, cost
How to use this calculator
Choose a wall configuration — single wall, L-shape (2 walls), U-shape (3 walls), or rectangle (4 walls). Enter length, height, and thickness in feet, inches, and fractions. Subtract window and door openings. Results update instantly with volume, weight, formwork area, and an interactive diagram.
Cost — pick ready-mix truck per yd³, 80 lb bags, or 60 lb bags for material cost.
Reinforcement — horizontal and vertical rebar #3–#6 with spacing 6″–24″ o.c. per ACI 318-19, including lap splices.
Labor — rate per ft² of formwork (contact area), per yd³, or flat price. Grand total sums all active sections.
Saved Calculations
| Time | Config | Length | Vol yd³ | Concrete $ | Rebar | Rebar $ | Labor | Total |
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How to Calculate Concrete for a Poured Wall
This concrete wall calculator estimates volume in cubic yards, number of pre-mixed bags (60 lb and 80 lb), total weight, formwork area, material cost, reinforcement requirements, and labor expenses for poured concrete walls. Choose from single wall, L-shape (2 walls), U-shape (3 walls), or rectangular (4 walls) configurations. Enter dimensions in feet, inches, and fractions, set wall thickness (standard: 8" for foundations, 10-12" for retaining walls), subtract door and window openings, and adjust waste allowance.
Wall Volume Formula
Wall Volume = Total Wall Length x Height x Thickness - (Number of Openings x Opening Width x Opening Height x Thickness). Convert to cubic yards by dividing cubic feet by 27. Concrete weighs approximately 150 lbs/ft³ (4,050 lbs/yd³). Formwork area equals wall surface area on both sides (2 x Length x Height), which determines forming material and labor needs.
Reinforcement per ACI 318-19
Walls require both horizontal and vertical reinforcement. ACI 318-19 Section 11.6 requires minimum steel ratio of 0.0012 for horizontal and 0.0015 for vertical bars. Typical residential: #4 bars at 12" o.c. each way. The calculator accounts for lap splices at 40 bar diameters, cutting waste, and standard 20 ft bar lengths.
Cost Estimation
Compare ready-mix delivery per cubic yard against bagged concrete. Walls are more labor-intensive than slabs due to formwork construction. Typical forming + pouring labor runs $8-15/ft² of contact area (both sides). The grand total combines concrete, rebar, and labor when multiple sections are active.
FAQ
How thick should a concrete wall be? Foundation walls: 8" minimum for up to 7 ft unbalanced fill; 10" for up to 8 ft; 12" for retaining walls over 8 ft of retained earth, per ACI 318-19 and IRC Table R404.1.2(1).
How much concrete do I need for a basement wall? A typical 30 ft x 20 ft basement with 8 ft high, 8" thick walls requires approximately 100 ft of perimeter x 8 ft x 0.67 ft = ~533 ft³ = ~19.7 yd³ before waste.
