Footing design calculator
Size footings and verify bearing capacity for foundations
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The Footing Design Calculator helps structural engineers size foundation footings based on column loads and soil bearing capacity. Calculate required footing dimensions, verify bearing pressure, and check structural design requirements.
Proper footing design ensures foundations safely transfer building loads to the ground without exceeding soil bearing capacity or causing excessive settlement. The calculator performs comprehensive checks including bearing capacity, punching shear, one-way shear, and flexure.
Enter column loads, soil bearing capacity, and footing dimensions to calculate bearing pressure, required reinforcement, and design checks. The tool helps optimize footing size while ensuring structural adequacy and code compliance for both square and rectangular footings.
Features
Everything you need
- Footing size calculation from loads
- Bearing capacity verification
- Punching shear analysis
- One-way shear checks
- Flexure and reinforcement design
- Square and rectangular footings
- Multiple soil type support
How it works
Simple workflow
- 1Enter column load and dimensions
- 2Specify soil bearing capacity
- 3Input footing dimensions or let calculator size
- 4Review bearing pressure and safety factors
- 5Check structural design requirements
Use cases
Built for real-world scenarios
Foundation design
Size footings for columns and walls during structural design to ensure adequate bearing capacity.
Preliminary sizing
Quickly estimate footing dimensions during early design phases before detailed analysis.
Code compliance
Verify footing designs meet structural code requirements for bearing, shear, and flexure.
Renovation assessments
Evaluate existing footing capacity when adding loads or modifying structures.
FAQ
Frequently asked questions
Footing area = Column Load ÷ Allowable Bearing Pressure. For a 100 kip load on 3,000 psf soil: Area = 100,000 lbs ÷ 3,000 psf = 33.3 sq ft. A 5.8' × 5.8' square footing would work.
Bearing capacity is the maximum pressure soil can safely support without excessive settlement or failure. Typical values: 2,000-4,000 psf for good soil, 1,000-2,000 psf for fair soil, less for poor soil.
Punching shear is the tendency for a column to 'punch through' the footing. Footing thickness must be sufficient to resist this force, typically requiring thicker footings for higher loads or weaker concrete.
Footing thickness depends on loads, soil bearing, and concrete strength. Typical residential footings are 8-12 inches thick. Commercial footings may be 12-24 inches or more. The calculator determines minimum required thickness.
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We're always looking to improve our calculators. If you have ideas for new features, improvements, or found something that could work better, we'd love to hear from you.
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