Structural Engineering
Footing Size Calculator
Calculate required footing size based on load and soil bearing capacity.
🏗️ Load & Soil
Total Load
kN
Total structural load on footing (kN)
Soil Bearing Capacity
kN/m²
Allowable soil bearing pressure
📐 Footing Type
Footing Shape
Square: equal sides, Rectangle: width × length, Circular: diameter
Footing Depth
m
Thickness of footing (for volume calculation)
⚙️ Advanced Options
Concrete Grade
Strength: M20 = 20 MPa
Safety Factor
Factor of safety for design
Area 0%
Required Area
0 m²
footing base area
Footing Size 0 m
Concrete Volume 0 m³
Bearing Pressure 0 kN/m²
Status ✅ Safe

📊 Footing Design Details

Parameter Value Unit

How the formula works

Required Area = (Load × Safety Factor) ÷ Soil Capacity  |  Pressure = Load ÷ Area
  • Required Area = Total Load × Safety Factor ÷ Soil Bearing Capacity
  • Square Footing = √(Area) × √(Area) (side length × side length)
  • Rectangular Footing = Width × Length (user-defined ratio, assumed 1:1.5)
  • Circular Footing = Diameter = 2 × √(Area ÷ π)
  • Concrete Volume = Area × Depth
  • Bearing Pressure = Load ÷ Actual Area (should be ≤ Soil Capacity)
  • Safety Factor = Applied to load for conservative design