Strap (cantilever) footing calculator

Inputs in the worked example

The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.

Worked example — results

• ✓ Interior reaction positive

Method, formulas and assumptions

• Exterior footing reaction P1 s/(s − e) = 700*6/(6-0.6) = 777.78 kN
• Interior footing reaction P2 − (R1 − P1) = 1000-(777.78-700) = 922.22 kN
• Exterior footing area = 777.78/250 = 3.1111 m²
• Interior footing area = 922.22/250 = 3.6889 m²
• Strap moment P1 e = 700*0.6 = 420 kNm

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