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Concrete Curb Calculator

Calculate concrete volume for curb and gutter systems, including barrier curbs, mountable curbs, and slab curbs. Supports various curb dimensions and gutter widths. Enter dimensions, select units and add waste to get instant, supplier-ready numbers.

1. Measurements & Dimensions

2. Material Properties & Waste Allowance

3. Optional Material Cost

CONCRETE CURB CALCULATOR ESTIMATE
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Enter dimensions above to calculate

Calculation Breakdown & StepsFormula: V = length × (curb width × full curb height + gutter width beyond curb × gutter thickness)
  1. Enter values to see step-by-step substitution.

    Engineering Assumptions:

    • The two cross-section rectangles must not overlap. Measure gutter width beyond the curb, excluding curb width.
    • For a tapered gutter or shaped curb, use the actual cross-section area from the section drawing.
    VISUAL GUIDE — CONCRETE CURB CALCULATORconcrete · concrete-curb-calculator

    CROSS-SECTION — Curb + Gutter

    Concrete Curb Calculator curb sectionCurb 6×6Gutter 18×66"

    PLAN VIEW — Length

    Concrete Curb Calculator curb planLength 20 ft1.0 ft² × Length = 20 ft³
    Concrete Curb Calculator — V = length × (curb width × full curb height + gutter width beyond curb × gutter thickness) · example 23×16 @3in = 92.0 ft³ (3.41 yd³) → 3.82 yd³ with 12% waste · concrete-curb-calculator

    What Is This Calculator?

    The Concrete Curb Calculator — Estimates concrete volume, weight and ready-mix versus bag count for US slabs, footings and walls.

    What Does It Calculate?

    • Concrete volume in cubic yards and cubic feet
    • Ready-mix loads vs 40/60/80-lb bags
    • Weight and cost with waste

    How to Use the Calculator

    1. Measure Curb 20 ft, 6x6 in curb + 18x6 in gutter — use feet for length/width and inches for thickness where typical.
    2. Enter values and select units. The calculator converts to feet before calculating (inches /12, yards x3).
    3. Adjust waste % and optional price, then click Calculate. Results show with waste included.
    4. Use Reset to clear and try another size.

    Formula & Engineering Methodology

    V = length × (curb width × full curb height + gutter width beyond curb × gutter thickness)

    • Length — Curb length in feet
    • Curb — Width x Height

    All units convert to exact standard engineering dimensions (NIST SP 811) before calculation to ensure consistency between US Customary and Metric measurements.

    Worked Example

    Example: Curb 20 ft, 6x6 in curb + 18x6 in gutter

    STEPVALUE
    Curb area0.5*0.5 = 0.25 ft2
    Gutter area1.5*0.5 = 0.75 ft2
    Volume20*1.0 = 20 ft3 = 0.74 yd3

    Construction Information

    Material: Concrete — 4000 psi typical for driveways, 3000 psi for patios. Ordered by cubic yard (27 ft³) or bags (0.60 ft³ per 80-lb). Keep slump 4 in for slabs.

    Curb and gutter combined — include gutter thickness. Add 10% for curves.

    Material Information

    Concrete — 4000 psi typical for driveways, 3000 psi for patios. Ordered by cubic yard (27 ft³) or bags (0.60 ft³ per 80-lb). Keep slump 4 in for slabs.

    Waste & Overages

    Add 5–10% for spillage and uneven subgrade — 10% is safe for hand-screeded forms.

    Practical Tips

    • Order ready-mix over ~1 yd³ (45 bags) — faster and cheaper
    • Keep subgrade compacted and forms braced
    • Add one extra bag per 10 as buffer

    Common Mistakes

    • Forgetting to convert inches to feet (4 in = 0.333 ft)
    • Ordering the theoretical minimum — second trip costs more than 10% waste

    Assumptions & Engineering References

    • The two cross-section rectangles must not overlap. Measure gutter width beyond the curb, excluding curb width.
    • For a tapered gutter or shaped curb, use the actual cross-section area from the section drawing.

    This calculator provides an estimate based on your inputs. Actual requirements vary by site, material and installation. For code-regulated or load-bearing work, consult a qualified professional.

    Calculations run 100% in your browser — zero tracking of your dimensions or input data.

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    Frequently asked questions

    What does the Concrete Curb Calculator calculate?

    The Concrete Curb Calculator estimates concrete curb quantity for US jobs — Concrete volume in cubic yards and cubic feet, Ready-mix loads vs 40/60/80-lb bags, Weight and cost with waste. Enter dimensions, choose units, add waste and price to get instant results.

    How do I measure for concrete curb?

    Measure curb 20 ft, 6x6 in curb + 18x6 in gutter on site. Use the unit selectors — the tool converts inches→feet (÷12) and yards→feet (×3) before math. For non-rectangular, split into rectangles and add.

    How much waste should I add?

    Add 5–10% for spillage and uneven subgrade — 10% is safe for hand-screeded forms.

    How accurate is this concrete curb estimate?

    Math is exact for your inputs. Actual needs vary by site, material and installation. Add 5–10% waste for rectangular, 10–15% for irregular.

    About Calculator Street

    Built by Vipul Otari for US homeowners & contractors. Calculator inputs are processed in your browser. Estimates depend on your measurements, product specifications and the assumptions shown on this page. Confirm order quantities with your supplier and structural requirements with your project designer. Page updated: 2026-09-11.

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