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Combined Footing Sizer

Size a two-column rectangular combined footing using the resultant-of-loads method to keep the soil pressure uniform.

Inputs

Sizing approach (rectangular)
  • Resultant location ̄x = (P1·0 + P2·s)/(P1+P2) from column 1.
  • For uniform pressure: footing length L = 2·(̄x + e1). Verify footing covers both columns.
  • Required area A = ΣP / qa. Required width B = A/L.
  • If trapezoid required (column 2 falls outside L), use trapezoidal proportion (not auto-handled).

Results

Total Load ΣP
Resultant ̄x from C1
Required Length L
Required Area A
Required Width Brq
Provided Pressure
Status