SettingsSettings for this calculationUS
The truss's calculated deflection under dead load alone.
Dead load only, from the truss designer's output — camber exists to take out the sag the permanent load causes, so live load does not belong here. Cambering for live load would leave the truss arched upward most of its life. The figure comes from the truss design rather than from a hand calculation, because a truss's deflection depends on its web layout and its plate slip as much as on its chords.
Recommended camber
0.585 in
1.5× is a commonly-used manufacturer rule of thumb — confirm your truss supplier's actual camber schedule for the specific span and load.
They open the calculator with your figures already in it
Wood Truss Camber Calculator: 0.585 in — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Show calculation logicHide calculation logic
How this was calculated
Formula source(s)
- Truss manufacturers commonly build in upward camber equal to approximately 1.5× the calculated dead-load deflection, to offset long-term sag and present a level/slightly-arched ceiling under dead load
Inputs used
- Calculated Dead-Load Deflection
- 0.39 in
Confidence note: 1.5× is a commonly-used manufacturer rule of thumb — confirm your truss supplier's actual camber schedule for the specific span and load.
What this calculation does not cover
- Camber changes the truss's SHAPE, not its stiffness. A truss cambered 15 mm (0.59 in) still deflects exactly as far under load as the same truss built flat — the sag simply starts from a hump instead of from level. If a truss is failing a span/deflection limit, camber does nothing for it; deeper chords, closer spacing or a shorter span do.
- It is a shop dimension and there is no site version of it. Camber is pressed in during fabrication, so it has to be on the truss order — a truss delivered flat cannot be cambered afterwards, and jacking one on the wall to fake it loads the connector plates in a direction they were never designed for.
- Nothing here covers what sits under the cambered bottom chord. As the camber goes out under dead load the chord travels down onto anything below it, so non-bearing partitions need a slip connection at the top rather than nails into the chord — fixed tight, that partition starts carrying roof load it was never framed for and the ceiling cracks in a line along it.
Add the equipment this sizes
This result is a specification — 0.585 in — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Truss manufacturers commonly build in upward camber equal to approximately 1.5× the calculated dead-load deflection, to offset long-term sag and present a level/slightly-arched ceiling under dead load
Cite this page
Your workspace
Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.