Header span calculator for wood framing
Design a wood header in Calcs.com. Start from the Roof Header or Floor Header preset, set your size and span, and check bending, shear, bearing and deflection to NDS 2024.
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How header design works in Calcs.com
The Roof Header or Floor Header preset sets up the Wood Beam (ASD, NDS 2024) calculator in Calcs.com, a standards-aligned calculation platform for structural engineers.
[ 01 ]
Start from the Roof Header or Floor Header preset
Choose Wood Beam (ASD), then Roof Header or Floor Header. You start from the member you're designing, with its loads and limits in place, rather than a blank beam. Roof Header and Floor Header set up a short built-up member over an opening, unbraced, with the roof, wall and, for Floor Header, floor loads stacked above it. Each value below is where the preset starts. You can change any of them.
Loads
Starts with Roof Load: dead 15 psf, snow 30 psf, roof live 20 psf, wind down 30 psf, wind up -30 psf over 14 ft; Wall Load: dead 15 psf over 2 ft. Change any value or width, or add line, point and moment loads.
Deflection limits
Starts at L/180 for live load and L/120 long term. Set the limits your project calls for.
Service condition
Starts dry. Set it to wet for a member that stays damp, which usually means exterior work.
Member and bracing
Starts as 2 plies, a non-repeating member, no continuous bracing for lateral torsional buckling. Change the plies or the bracing to match your framing.
[ 02 ]
Change it to your header
Pick a size and grade from the standard sections database, enter a custom section, or let Autosize choose one. Then set the plies, span, supports and bracing.
Size and grade
Standard lumber, glulam, LVL, PSL and LSL sections, or a custom section, with Autosize beside the size field.
Span and supports
Plan length, support type, position and bearing length for each support.
Bracing and flitch plates
Continuous bracing for lateral torsional buckling, and optional flitch plates.
[ 03 ]
See every check as you design
Bending, shear and bearing utilization sit at the top of the sheet. Deflection is checked against the limits the preset sets.
Try the roof header preset: change the size and span
Pick a size and a span. The sheet shows what the Wood Beam (ASD, NDS 2024) calculator returned for that roof header.
Utilization at a glance
Bending, shear and bearing as percentages at the top of the sheet, as in the calculator.
Deflection against the preset's limits
Live load and long-term deflection checked against L/180 and L/120.
Every check, as the calculator prints it
Moment, shear and bearing utilization and both deflections, with the value behind each percentage.
14-day free trial • No credit card required
Wood Beam (ASD, NDS 2024) - Roof HeaderSavedJ1Key Properties
Checks
Plies, spacing, loads and bracing are as the Roof Header preset sets them. Every input is editable in the calculator. This sheet replays 9 solves by the Calcs.com engine on 2026-11-12: 3 sizes by 3 spans. In the calculator, any size, span, spacing or load is solved the same way.
Roof header span table: 2x8 to 2x12
Each cell is the Roof Header preset solved in the Wood Beam (ASD, NDS 2024) calculator at that size and span, with every other input as the preset sets it. It shows the governing check's ratio. Above 1.00 fails.
| Member | 4 ft | 6 ft | 8 ft |
|---|---|---|---|
| 2x8 x 2 | 0.39BendingPasses | 0.82BendingPasses | 1.45BendingFails |
| 2x10 x 2 | 0.28ShearPasses | 0.55BendingPasses | 0.98BendingPasses |
| 2x12 x 2 | 0.25BearingPasses | 0.41BendingPasses | 0.74BendingPasses |
Try the floor header preset: change the size and span
Pick a size and a span. The sheet shows what the Wood Beam (ASD, NDS 2024) calculator returned for that floor header.
Utilization at a glance
Bending, shear and bearing as percentages at the top of the sheet, as in the calculator.
Deflection against the preset's limits
Live load and long-term deflection checked against L/360 and L/240.
Every check, as the calculator prints it
Moment, shear and bearing utilization and both deflections, with the value behind each percentage.
14-day free trial • No credit card required
Wood Beam (ASD, NDS 2024) - Floor HeaderSavedJ1Key Properties
Checks
Plies, spacing, loads and bracing are as the Floor Header preset sets them. Every input is editable in the calculator. This sheet replays 9 solves by the Calcs.com engine on 2026-11-12: 3 sizes by 3 spans. In the calculator, any size, span, spacing or load is solved the same way.
Floor header span table: 2x8 to 2x12
Each cell is the Floor Header preset solved in the Wood Beam (ASD, NDS 2024) calculator at that size and span, with every other input as the preset sets it. It shows the governing check's ratio. Above 1.00 fails.
| Member | 4 ft | 6 ft | 8 ft |
|---|---|---|---|
| 2x8 x 3 | 0.48ShearPasses | 0.95BendingPasses | 1.68BendingFails |
| 2x10 x 3 | 0.38ShearPasses | 0.64BendingPasses | 1.13BendingFails |
| 2x12 x 3 | 0.31ShearPasses | 0.47BendingPasses | 0.85BendingPasses |
13 presets on one wood beam calculator
Each member preset, from Floor Joist to Deck Beam, sets up the same calculator with its own loads and deflection limits. Rafter and Hip / Valley put the member on a slope. Deck Joist and Deck Beam set wet service.
Generic Beam
Generic Flitch Beam
Floor Joist
Floor Girder
Ceiling Joist
Hip / Valley
Rafter
Ridge Beam
Combination Beam
Deck Joist
Deck Beam
Open the Roof Header or Floor Header preset in the calculator
- [ 01 ]Start your free trial. You land on the app's home page.
- [ 02 ]Open the Wood Beam (ASD) calculator for the edition you design to.
- [ 03 ]Choose Roof Header or Floor Header from its presets. Its values load in, ready to change.
14-day free trial • No credit card required
Pick the edition you design to. The sheet and the steps above follow it, and each edition has a Roof Header or Floor Header preset.
These results use the preset's loads and limits. Check every input against your project before you rely on a result. The engineer of record stays responsible for the design.
Frequently asked questions
Design your header in Calcs.com
Start from the Roof Header or Floor Header preset and check your size and span to NDS 2024.
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