This concrete slab wall load calculator gives a first-pass estimate of the maximum wall (line) load a concrete slab or footing can carry, based on the allowable soil bearing pressure and the bearing width. It is a planning aid, not a design tool.
How is it estimated?
Allowable line load (lb/ft) = Allowable bearing pressure (psf) × Bearing width (ft)
- Allowable bearing pressure — safe soil pressure from a geotechnical report (psf)
- Bearing width — width of the footing or thickened slab edge under the wall
Example calculation
For a soil bearing of 2,000 psf and a footing width of 1.5 ft:
- Line load = 2,000 × 1.5 = 3,000 lb/ft
Real capacity also depends on slab thickness, concrete strength, reinforcement, and punching-shear checks.
Important
This is an estimate for early planning only and is not structural advice. Any load-bearing slab, footing, or wall must be designed by a licensed structural engineer to your local building code.
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Frequently Asked Questions
How much load can a concrete slab support?
As a first estimate, multiply the allowable soil bearing pressure by the footing or bearing width. Final capacity depends on slab thickness, concrete strength, and subgrade.
What is allowable soil bearing pressure?
It is the safe load per unit area the soil can carry, often 1,500 to 3,000 psf for typical soils. A geotechnical report gives the value for your site.
Is this a substitute for engineering?
No. This is a planning estimate only. A licensed structural engineer must size any load-bearing slab or footing to code.