Home & Construction
Foundation Load Calculator
Combine vertical load components, divide by effective area, and expose utilization and remaining service-load margin without presenting a structural or geotechnical design.
Total service vertical load-
Service bearing pressure (kPa)-
Factored vertical load (kN)-
Factored bearing pressure (kPa)-
Load at entered allowable pressure (kN)-
Service pressure utilization-
Illustrative ultimate bearing reference (kPa)-
Allowable service load minus service load-
Decision view
Foundation load and bearing-pressure path
Foundation load and bearing-pressure pathService and user-factored pressure are compared with the exact entered allowable soil pressure.
Exact scenario comparisonEffective bearing area (m2) changes while all other entered assumptions remain constant.
| Effective bearing area (m2) | Total service vertical load | Service bearing pressure (kPa) | Factored vertical load (kN) | Factored bearing pressure (kPa) | Load at entered allowable pressure (kN) | Service pressure utilization | Illustrative ultimate bearing reference (kPa) | Allowable service load minus service load |
|---|
How to use Foundation Load Calculator
- Use loads and area from the same foundation system.
- Confirm whether the allowable pressure is net or gross.
- Have settlement, eccentricity, and code combinations reviewed professionally.
Calculator guide
Understanding Foundation Load Calculator
Foundation bearing review begins by separating service demand, user-factored demand, and the entered allowable soil pressure.
Calculation method
How the calculation works
Combine entered vertical load components, calculate service and user-factored bearing pressures, and compare service demand with an entered allowable soil pressure. Add service loads, apply the entered factors to the selected components, divide both totals by bearing area, and compare service pressure with the entered allowable value.
Engineering boundary
What the average-pressure check cannot see
Real foundation performance depends on geometry and soil behavior beyond one ratio.
Worked situations
Practical examples
- Increasing area lowers average bearing pressure.
- Factored pressure is shown separately from service utilization.
- The ultimate reference is only allowable pressure multiplied by the entered planning factor.
Better inputs
Useful tips
- Use a geotechnical report.
- Check load eccentricity.
- Review groundwater and layered soil.
Before relying on the result
Limitations and common mistakes
- Settlement, punching, sliding, overturning, uplift, eccentricity, groundwater, seismic action, layered soils, and code combinations are excluded.
- Uniform pressure is assumed.
- This is not a foundation design.
Reference
Key terms
- Service pressure
- Unfactored vertical load divided by effective area.
- Allowable pressure
- User-entered service-level soil bearing reference.
- Utilization
- Service pressure divided by allowable pressure.
- Bearing margin
- Allowable service load minus entered service load.
Important note
Calculated from the entered measurements and stated coverage or quantity rules. Confirm field dimensions, waste, product requirements, structural conditions, and local codes before purchasing or building.
Frequently asked questions
Is allowable pressure calculated here?
No, it is entered by the user.
Why show factored pressure?
It provides a separate demand reference using entered factors.
Does margin guarantee safety?
No.
Can this size a footing?
Not without professional geotechnical and structural design.