Determine the load on a bearing wall from floor, roof, and live loads using tributary widths. Helps with header and footing design.
Load-bearing walls carry weight from the structure above and transfer it to the foundation below. Accurately calculating the load on a bearing wall is essential for sizing the wall studs, headers, and the foundation footing beneath it. The load comes from three main sources: the dead load (weight of materials), the live load (occupancy and use), and sometimes snow or wind loads.
This calculator computes the total load per linear foot on a bearing wall by summing the tributary loads from each supported level. You enter the tributary width (the distance of floor or roof that the wall supports) and the design loads for each level, and the calculator sums them into a total wall load.
Knowing the wall load is the first step in determining whether standard 2×4 studs at 16″ OC are adequate, or whether 2×6 studs, double top plates, or additional engineering are needed.
This measurement supports better project estimation, enabling contractors and engineers to deliver accurate bids and avoid costly overruns during the construction process.
Understanding the load on a bearing wall drives decisions about stud size, header design, and foundation footings. This calculator simplifies the tributary load calculation so you can quickly evaluate different framing scenarios. Regular use of this calculation supports compliance with building codes and inspection requirements, helping projects proceed smoothly through the permitting and approval process.
Load per foot = Σ(tributary width × (dead load + live load)) for each level Total wall load (plf) = roof load/ft + floor load/ft + wall self-weight
Result: 739 plf total wall load
Roof: 12×(15+20) = 420 plf. Floor: 6×(12+40) = 312 plf. Wall self-weight: 7 plf. Total = 420+312+7 = 739 plf.
For a first-floor bearing wall in a two-story home, the load includes: roof dead and live/snow loads, second-floor dead and live loads, first-floor dead load, and wall self-weights for both stories. Each level adds its tributary contribution. The first-floor wall and its footing must support the entire cumulative load.
When a bearing wall has window or door openings, the load over the opening must be carried by a header beam. The header supports the wall load for its span and transfers it through jack studs to the foundation. Header sizing depends on both the span and the total wall load.
The footing beneath a bearing wall must be wide enough to spread the wall load over the soil without exceeding the soil's bearing capacity (typically 1,500–4,000 psf for common soil types). Footing width = wall load (plf) / soil bearing capacity (psf).
Bearing walls typically run perpendicular to floor joists and support the ends or midspan of joists or trusses. They stack from roof to foundation. Walls parallel to joists are usually non-bearing unless they carry a beam above.
Tributary width is the distance of floor or roof area that depends on the wall for support. For an interior wall with equal joist spans on both sides, it's half the span on each side combined.
Typical residential floor dead load is 10–15 psf, including joists, subfloor, and finish flooring. If there's tile flooring or heavy partitions above, add 5–15 psf more.
The IRC specifies 40 psf for habitable rooms, 30 psf for sleeping rooms (where allowed), and 10 psf for uninhabitable attics. Balconies and decks may be 40–60 psf depending on the jurisdiction.
Yes, but you must install a beam (header) to replace the wall's structural function. The beam must be sized by an engineer to carry the same total load. Temporary shoring is required during construction.
In snow regions, the ground snow load is converted to a roof snow load using factors for exposure and slope. This is added as a live load component on the roof. In heavy snow areas (50+ psf ground snow), this can be the dominant load on the wall.