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Board Foot Calculator

Calculate board foot — board feet from thickness, width, length and count with waste for US projects. 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

BOARD FOOT CALCULATOR ESTIMATE
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Enter dimensions above to calculate

Calculation Breakdown & StepsFormula: Board feet = thickness(in) × width(in) × length(ft) × quantity / 12.
  1. Enter values to see step-by-step substitution.

    Engineering Assumptions:

    • One board foot is 144 in³. Use nominal or actual dimensions consistently with the seller’s pricing convention.
    • This is volume pricing, not a cutting plan or a count of framing members. Price is dollars per board foot.
    VISUAL GUIDE — BOARD FOOT CALCULATORframing · board-foot-calculator

    TOP VIEW — Board thickness used for pricing × Board width used for pricing

    Board Foot Calculator topBoard thickness used for pricing 12inBoard width used for pricingBoard Foot12×17 = 204 in²

    SECTION — Board length 4ft

    Board Foot Calculator sectionBoard Foot 4ft4"Board feet = thickness(in) × width(in) × length(ft) × quantity / 12. · +5% → 2.64 yd³
    Board Foot Calculator — Board feet = thickness(in) × width(in) × length(ft) × quantity / 12. · example 12×17 @4ft = 68.0 ft³ (2.52 yd³) → 2.64 yd³ with 5% waste · board-foot-calculator

    What Is This Calculator?

    The Board Foot Calculator — Frames US walls and floors — studs, joists, headers, beams and board feet.

    What Does It Calculate?

    • Stud count from spacing
    • Board feet (T x W x L /12)
    • Joist/beam loads with waste

    How to Use the Calculator

    1. Measure Wall 20 ft, studs 16 in OC — 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

    Board feet = thickness(in) × width(in) × length(ft) × quantity / 12.

    • Spacing — 16 or 24 in on-center
    • Board — Thickness*Width*Length/12

    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: Wall 20 ft, studs 16 in OC

    STEPVALUE
    Studsceil(20*12/16)+1 =16
    Board feet 2x4x81.5*3.5*96/144 =3.5 bf
    With waste18 studs

    Construction Information

    Material: Studs 2x4/2x6, 16 in o.c. typical. SPF #2, 1.5x3.5 in actual. Board foot = 1x12x12 in.

    Studs 16 in OC, 24 in non-load. Add cripples, headers per opening.

    Material Information

    Studs 2x4/2x6, 16 in o.c. typical. SPF #2, 1.5x3.5 in actual. Board foot = 1x12x12 in.

    Waste & Overages

    Add 10% for cuts and cripples — 15% for gable walls.

    Practical Tips

    • Add 1 stud per corner and opening
    • Crown joists up

    Common Mistakes

    • 16 in vs 24 in o.c. — count off 30%
    • Forgetting cripples under sills

    Assumptions & Engineering References

    • One board foot is 144 in³. Use nominal or actual dimensions consistently with the seller’s pricing convention.
    • This is volume pricing, not a cutting plan or a count of framing members. Price is dollars per board foot.

    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 Board Foot Calculator calculate?

    The Board Foot Calculator estimates board foot quantity for US jobs — Stud count from spacing, Board feet (T x W x L /12), Joist/beam loads with waste. Enter dimensions, choose units, add waste and price to get instant results.

    How do I measure for board foot?

    Measure wall 20 ft, studs 16 in oc 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 cripples — 15% for gable walls.

    How accurate is this board foot 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