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LS Building Products
LS Building Products

Door Header Size Calculator

Door Header Size Calculator

I want to find the...

Header span estimator

in
 
 

This calculator is for general informational purposes only. Verify all results with a licensed contractor or structural engineer. Actual requirements depend on species/grade, loading (roof/floor), number of plies, tributary width, wind/snow, and local code.

Key Features

✔ Two calculation modes — find the maximum header span for a selected size or get a recommended header size for a required opening.
✔ Wide unit support — inches, feet, yards, millimeters, centimeters, meters, plus compound entry ft/in and m/cm.
✔ Smart input handling — accepts compound formats (e.g., “8 6” for 8 ft 6 in) and formats results with 1/4-inch or 0.1-cm precision.
✔ Instant conversions & notes — automatic unit conversion with helpful hints under each result.
✔ One-click sharing — copy a clean summary of your inputs and results for quotes or site notes.
✔ Clear / reload controls — reset fields or reload the calculator at any time.

How to Use It

  1. Choose your goal:
    Use the “I want to find the…” dropdown to select maximum header span or recommended header size.
  2. If finding maximum span:
    Pick a header size (e.g., 4"×6"). Select your preferred output unit — the calculator shows the estimated maximum span.
  3. If getting a recommended size:
    Enter the required clear span of the opening and choose its unit (supports ft/in or m/cm). The tool suggests the smallest listed size whose estimated capacity meets or exceeds your span.
  4. Review assumptions:
    Estimates use the common rule of thumb for solid-sawn wood: maximum span (ft) ≈ header depth (in). Always confirm with approved span tables or an engineer.
  5. Share or reset:
    Click “Share result” to copy a summary. Use “Clear all fields” to reset inputs or “Reload calculator” to start fresh.

Build with Confidence

The Door Header Size Calculator streamlines early planning for door and window openings, helping you scope materials quickly. For permitted work, verify final sizes using code-approved span tables or a licensed professional.

Start framing smarter with the Door Header Size Calculator today.

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