Foundation Design Calculators
Spread footings, combined footings, pile capacity, settlement checks.
Footing and Soil Inputs
Advanced Settings
How to Use This Calculator
Enter the vertical loads, the supporting area, and the soil bearing capacity. Use the extra load field to model construction stages or concentrated live loads, and adjust the factor of safety to align with your design code.
The soil type selector is informational; you can note the dominant behavior for documentation without affecting the numeric result.
Methodology
This tool computes applied pressure (load over area) and compares it to the allowable bearing pressure, factoring in the requested safety multiplier. The required footing area reverses the allowable capacity to check whether the current load demand is within tolerance.
- The safety margin is the remaining ksf between allowable capacity and applied pressure; negative values flag overstress.
- Extra load stages are spread evenly across 12 rows in the pressure schedule to show how incremental loading consumes capacity.
- Required footing area assumes uniform load distribution and does not replace a full geotechnical analysis.
Full original guide (expanded)
Original content highlighted a suite of foundation design calculators focused on spread footings, combined footings, pile capacity, and settlement checks.
- Spread Footing: Bearing pressure, sliding, and overturning for individual square or rectangular footings.
- Combined Footing: Load distribution strategies and geometry for wall-supported combined footings.
- Pile Capacity: Static pile-settlement relationships, α/β/λ methods, and allowable load adjustments.
- Settlement: Immediate and consolidation settlement estimates for layered soils and foundation loads.
The earlier layout described navigation, audit status, and formula placeholders that are now consolidated into this canonical presentation.