Deduct large openings deliberately
Small blockouts may not change the order much after waste, but large doors, windows, or utility openings should be estimated separately so the volume is not overstated.
concrete
Concrete Wall Calculator
Estimate concrete yards for wall pours using length, height, and thickness.
Estimated concrete neededLength, width, and thickness are required before the estimate appears.
Example20 ft wall x 8 ft high x 6 in thick = about 2.96 yd³
Wall and retaining work may need engineering, reinforcement, and local code review.
Last reviewed: May 12, 2026 by the BuilderCalc editorial team.
SSR formula reference
Concrete Wall Calculator formulas
These formulas are rendered in the server HTML so crawlers, LLMs, and users can read the method without running JavaScript. The interactive calculator can change the inputs, but the estimating math below is visible in the raw page source.
Volume (cubic feet) = Length x width x thickness (in inches / 12).
Volume (cubic yards) = Cubic feet / 27.
Bags (80-lb) = Cubic feet / 0.60, rounded up.
80-lb bag yields about 0.60 ft3, or 0.022 yd3.
| Result | Formula |
|---|---|
| Volume in cubic feet | Length x width x thickness in feet |
| Thickness in feet | Thickness in inches / 12 |
| Volume in cubic yards | Cubic feet / 27 |
| 80-lb bags | Cubic feet / 0.60, rounded up |
| Ready-mix order | Cubic yards x (1 + waste percent) |
Standard PSI by application
| Application | Recommended PSI |
|---|---|
| Patio or walkway | 3,000 PSI |
| Garage floor, residential | 3,500 PSI |
| Driveway, cars | 3,500 to 4,000 PSI |
| Driveway, trucks or RVs | 4,000 to 4,500 PSI |
| Foundations and footings | 3,000 to 4,000 PSI, per plan and code |
Bag yield reference
| Bag size | Common yield |
|---|---|
| 80-lb bag | About 0.60 ft3, or 0.022 yd3 |
| 60-lb bag | About 0.45 ft3, or 0.017 yd3 |
| 50-lb bag | About 0.375 ft3, or 0.0138 yd3 |
| 40-lb bag | About 0.30 ft3, or 0.011 yd3 |
Wall planning
Concrete Wall Calculator planning notes
Wall volume uses length, height, and thickness, but wall pours also need attention to openings, reinforcement, forms, and pressure from fresh concrete.
Retaining walls need design review
Soil pressure, drainage, reinforcement, footing size, and wall height can all control the final design. Use this page for quantity planning, not structural approval.
How to use it
Keep the estimate tied to field measurements
Measure wall volume
Use wall length, height, and thickness in feet. Deduct large formed openings when they change volume meaningfully.
Confirm form and reinforcement
Wall pours need form bracing, reinforcement, and placement planning before the concrete quantity becomes actionable.
Plan placement method
Pump, chute, or bucket placement can affect waste, access, timing, and total delivered cost.
Related calculators
FAQ
Concrete estimating questions
How do I calculate concrete for a wall?
Multiply wall length by height by thickness, all in feet, then divide by 27 for cubic yards. Deduct large openings if they materially change the volume.
Should I subtract windows and doors?
Deduct large openings when they are clearly formed out. Small openings may be covered by the waste allowance, but large doors or utility blockouts should be estimated separately.
Can this calculator design a retaining wall?
No. Retaining walls require drainage, footing, reinforcement, soil, and load design. Use the result for concrete quantity planning only.
How much waste should I add for wall pours?
A 5-10% allowance is common for planning, but complex forms, pump lines, and blockouts can justify more.