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Retaining Wall Calculator

Calculate retaining wall — units per wall area with mortar joint, weight and cost with waste. Enter landscaping dimensions to get instant results. 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

RETAINING WALL CALCULATOR ESTIMATE
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Enter dimensions above to calculate

Calculation Breakdown & StepsFormula: Net wall area = length × height − openings; units = ceil(net area × allowance factor / ((unit length + joint) × (unit height + joint))).
  1. Enter values to see step-by-step substitution.

    Engineering Assumptions:

    • Use the exposed face dimensions, not the unit depth. Defaults describe one wythe of modular brick.
    • A nominal 16 × 8 in CMU face includes its joints: enter actual dimensions 15⅝ × 7⅝ in with a ⅜ in joint.
    • This is an area estimate. Corners, returns, lintels, bond patterns, caps and special units require a separate takeoff.
    VISUAL GUIDE — RETAINING WALL CALCULATORlandscaping · retaining-wall-calculator

    TOP VIEW — Wall length × Wall height

    Retaining Wall Calculator topWall length 11ftWall heightRetaining Wall11×15 = 165 ft²

    SECTION — Openings / excluded area 10ft2

    Retaining Wall Calculator sectionRetaining Wall 10ft210"Net wall area = length × height − openings; units = ceil(net area × allowance factor / ((unit length + joint) × (unit height + joint))). · +7% → 5.45 yd³
    Retaining Wall Calculator — Net wall area = length × height − openings; units = ceil(net area × allowance factor / ((unit length + joint) × (unit height + joint))). · example 11×15 @10ft2 = 137.5 ft³ (5.09 yd³) → 5.45 yd³ with 7% waste · retaining-wall-calculator

    What Is This Calculator?

    The Retaining Wall Calculator — Hardscape for US yards — pavers, base, sand, mulch and retaining walls.

    What Does It Calculate?

    • Paver count from area / paver area
    • Base gravel and sand volume
    • Mulch yards vs bags

    How to Use the Calculator

    1. Measure Patio 12x10 ft =120 ft2, paver 12x12 in — 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

    Net wall area = length × height − openings; units = ceil(net area × allowance factor / ((unit length + joint) × (unit height + joint))).

    • Area — Length*Width ft2
    • Paver area — 12x12=1 ft2, 4x8=0.222 ft2

    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: Patio 12x10 ft =120 ft2, paver 12x12 in

    STEPVALUE
    Pavers120/1 =120
    With 10% waste132 pavers
    Base 4 in120*0.333/27 =1.48 yd3

    Construction Information

    Material: Pavers 12x12 in =1 ft2, base 4 in gravel, 1 in sand. Mulch 2 ft3 bag =8 ft2 at 3 in.

    Base 4 in patio, 6-8 in driveway. Sand 1 in screeded. Waste 10% rect, 15% curve.

    Material Information

    Pavers 12x12 in =1 ft2, base 4 in gravel, 1 in sand. Mulch 2 ft3 bag =8 ft2 at 3 in.

    Waste & Overages

    Add 10% for cuts and curves — 15% for radial patterns.

    Practical Tips

    • Compact base in 2 in lifts
    • Edge restraint prevents shift

    Common Mistakes

    • No base — pavers settle
    • Thin mulch — weeds poke through

    Assumptions & Engineering References

    • Use the exposed face dimensions, not the unit depth. Defaults describe one wythe of modular brick.
    • A nominal 16 × 8 in CMU face includes its joints: enter actual dimensions 15⅝ × 7⅝ in with a ⅜ in joint.
    • This is an area estimate. Corners, returns, lintels, bond patterns, caps and special units require a separate takeoff.

    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 Retaining Wall Calculator calculate?

    The Retaining Wall Calculator estimates retaining wall quantity for US jobs — Paver count from area / paver area, Base gravel and sand volume, Mulch yards vs bags. Enter dimensions, choose units, add waste and price to get instant results.

    How do I measure for retaining wall?

    Measure patio 12x10 ft =120 ft2, paver 12x12 in 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 10% for cuts and curves — 15% for radial patterns.

    How accurate is this retaining wall 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.

    Free·Fast·Mobile-friendly·US units·Reviewed