Use this geological calculation for a transparent first-pass interpretation of measured rock, soil, fluid, well, stratigraphic, isotopic, geophysical, or seismic data under an explicitly selected model.

c

Soil cohesion c in kPa.

phi

Friction angle phi in degrees.

q

Effective surcharge q at footing base level in kPa.

gamma

Bulk unit weight gamma in kN/m3.

B

Footing width B in m.

Ultimate bearing capacity of a shallow strip footing qu = c*Nc + q*Nq + 0.5*gamma*B*Ngamma. Factors: Nq = exp(pi*tan(phi))*tan^2(45 + phi/2), Nc = (Nq - 1)*cot(phi), Ngamma = 2*(Nq + 1)*tan(phi) (Vesic convention for Ngamma; Terzaghi's original third factor differs). Base equation without shape or depth corrections. c and q in kPa, gamma in kN/m3, B in m. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Nc

Bearing capacity factor Nc.

Nq

Bearing capacity factor Nq.

Ngamma

Third bearing capacity factor Ngamma (Vesic convention).

qu

Ultimate bearing capacity qu in kPa.

• Geotechnical correlations and idealized failure models depend on stratigraphy, sampling disturbance, drainage, stress history, groundwater, density, anisotropy, scale, construction sequence, and laboratory or field method. Site-specific design requires investigation and code factors.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Compare independent measurements and models, retain units and analytical metadata, propagate uncertainty, and validate interpretations against logs, cores, maps, laboratory data, or field observations.

• Bearing Capacity Meyerhof Calculator

  Ultimate bearing capacity of a shallow strip footing on the Meyerhof (1963) base equation qu = c*Nc + q*Nq + 0.5*gamma*B*Ngamma with Nq = exp(pi*tan(phi))*tan^2(45 + phi/2), Nc = (Nq - 1)*cot(phi) and Meyerhof's Ngamma = (Nq - 1)*tan(1.4*phi). Base equation only: no shape or depth correction factors applied. c and q in kPa, gamma in kN/m3, B in m.

• Bearing Capacity Vesic Calculator

  Ultimate bearing capacity with Vesic (1973) shape and depth factors: qu = c*Nc*sc*dc + q*sq*dq + 0.5*gamma*B*Ngamma*sGamma, dGamma = 1. Factors Nq = exp(pi*tan(phi))*tan^2(45 + phi/2), Nc = (Nq - 1)*cot(phi), Ngamma = 2*(Nq + 1)*tan(phi) (Vesic convention). Shape factors sc = 1 + (B/L)*(Nq/Nc), sq = 1 + (B/L)*tan(phi), sGamma = 1 - 0.4*B/L; depth factors dq = 1 + 2*tan(phi)*(1 - sin(phi))^2*Df/B and dc = dq - (1 - dq)/(Nc*tan(phi)). c and q in kPa, gamma in kN/m3, lengths in m.

• Bearing Capacity Factor Ngamma Calculator

  Unit-weight bearing capacity factor Ngamma = 2 * (Nq + 1) * tan(phi) with Nq = tan^2(45 + phi/2) * exp(pi * tan(phi)); this is the Vesic (1973) convention, which differs from Terzaghi's and Meyerhof's original third factors. Equals 0 at phi = 0.