Footing + Moment

Spread footing under axial + moment — bearing distribution, shear & flexure (ACI/IBC).

Soil bearing is checked with service loads (P, M); shear & flexure are designed with factored loads (Pu, Mu). q_allow is a geotechnical (service) input.

Design diagram — updates live with your inputs

Footing & Column

Footing length L (ft)i In the moment direction

Footing width B (ft)i

Thickness (in)i

Column width (in)i Along L

Materials

Concrete f'c (psi)i

Steel fy (psi)i

Flexural bari

Service Loads (bearing)

Service axial P (kip)i Unfactored

Service moment M (kip-ft)i Unfactored

Allowable bearing (psf)i

Factored Loads (design)

Factored axial Pu (kip)i

Factored moment Mu (kip-ft)i

ACI 318-19

Validation, assumptions & limitations Download validation report (PDF) ↗

This calculator is verified by 4 independent tests comparing its output against closed-form statics, NDS/SDPWS design-standard values and published worked examples. Full case-by-case results are in the PDF report.

Assumptions

Service loads for bearing; factored loads for RC design.
Rigid footing, linear soil-pressure distribution.
e = 0.6 ft <= L/6 = 1.33 ft -> full contact (trapezoid).

Limitations

Concentric punching governs at low e (checked separately here).
Soil q_allow is a geotechnical service input.

Results are for preliminary design and must be confirmed by a licensed engineer against the current adopted code and project-specific conditions.