Slab Load Calculator

Estimate concrete slab self-weight, slab dead load, live load, superimposed load, total slab load, load per square foot, load per support, soil pressure, and simplified slab load utilization. Use this slab load calculator for concrete slabs, garage slabs, patios, floor slabs, slab-on-grade checks, and preliminary structural planning.

Calculate Slab Load

Slab self-weight PSF = slab thickness in feet × concrete density. Total slab load = slab area × total PSF + point loads.
Your result will appear here.

How the slab load calculator works

Slab self-weight:
The calculator multiplies slab thickness by concrete density to estimate the slab’s own weight in pounds per square foot.

Total area load:
The calculator adds self-weight, superimposed dead load, live load, and storage or equipment load.

Total slab load:
The calculator multiplies total PSF by slab area, then adds any additional point load.

Support and bearing check:
The calculator estimates load per support and bearing pressure over the selected bearing area.

Why use a slab load calculator?

A slab load calculator helps estimate how much weight a slab carries and transfers to soil, beams, columns, walls, or supports.

It can help compare slab self-weight, live load, dead load, total load, point load pressure, load per support, and simplified bearing utilization.

What your result means

Your result shows estimated slab area, slab self-weight PSF, superimposed dead load, live load, storage load, total area load, total slab load, point load pressure, load per support, bearing pressure, and simplified bearing utilization. These are planning estimates only.

Slab load formulas

Frequently asked questions

How do you calculate concrete slab self-weight?

Convert slab thickness to feet, then multiply by concrete density. For example, a 4-inch slab is 0.333 feet thick, and 0.333 × 145 PCF is about 48 PSF.

What is slab load?

Slab load is the total weight carried by a slab. It can include the slab’s own weight, finishes, partitions, storage, people, vehicles, equipment, and point loads.

Is slab load the same as slab capacity?

No. This calculator estimates load, not structural capacity. Slab capacity depends on concrete strength, reinforcement, thickness, subgrade support, span, cracking, punching shear, and code requirements.

Can this replace slab design?

No. Final slab design should account for soil/subgrade conditions, reinforcement, control joints, slab thickness, concrete strength, curing, punching shear, flexure, settlement, moisture, and local code requirements.