Calculate concrete volume, weight, cost, reinforcement, and labor for rectangular, circular, triangular, and L-shaped slabs with detailed material estimates, visual diagrams, and PDF/JPG/CSV export.
Saved Calculations
| Time | Shape | Area ft² | Vol yd³ | Concrete $ | Rebar | Qty | Rebar $ | Labor | Total |
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Concrete Slab Calculator helps homeowners, contractors, and builders estimate everything needed for a concrete pour in one place. Enter your slab dimensions in feet, inches, and fractions (⅛″ precision), choose from four shapes — rectangle, circle, triangle, or L-shape — and set thickness and waste allowance. The calculator instantly shows volume, area, weight, and an interactive diagram with plan view and cross-section.
Results display in your preferred unit: cubic yards, cubic feet, 80-lb bags, or 60-lb bags. Three optional sections expand the estimate when needed:
Cost — choose one pricing mode (ready-mix truck per yd³, 80-lb bags, or 60-lb bags) and get the total material cost without clutter.
Reinforcement — select from four welded wire mesh types (6×6 and 4×4 in light to extra-heavy gauges) or four rebar sizes (#3 through #6) with spacing from 6″ to 24″ o.c. The calculator accounts for lap splices per ACI 318-19, mesh overlap, and cutting waste (5–20%), then shows how many sheets or 20′ bars to buy, total weight, and cost.
Labor — enter a rate per square foot, per cubic yard, or a flat price for the job. The result includes total labor cost and a normalized $/ft² for easy comparison across bids.
When two or more cost sections are active, a Grand Total sums materials, reinforcement, and labor with a full breakdown. Save any calculation to the built-in history table and export results as formatted text (clipboard), CSV, A4 portrait JPG, or a single-page PDF with diagram and data.
Quick reference. Standard thickness: 4″ patios, 5–6″ driveways, 8″ heavy-duty. Waste: 5% simple pours, 10% typical, 15–20% complex shapes. One 80-lb bag ≈ 0.6 ft³; one 60-lb bag ≈ 0.45 ft³. Projects under 1–2 yd³ are practical with bags; larger pours are cheaper by truck. Welded wire mesh suits most 4″ slabs on grade; rebar #4 at 12″ o.c. is standard for driveways. All reinforcement follows ACI 318-19 guidelines — consult a structural engineer for load-bearing applications.
