Foundations · Pad, strip & combined footings

Bearing capacity calculator

Ultimate and allowable bearing pressure for strip or rectangular footings with shape and depth factors.

Standard: Terzaghi / Meyerhof / Vesic

Inputs in the worked example

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

Diagram for the worked example

Nq = e^(π tanφ) tan²(45 + φ/2); Nc = (Nq − 1) cot φ (5.14 for φ = 0)
Nγ = 2(Nq + 1) tan φ (Vesic) or (Nq − 1) tan(1.4φ) (Meyerhof)
Meyerhof shape: sc = 1 + 0.2Kp B/L; sq = sγ = 1 + 0.1Kp B/L (φ > 10°)
Depth: dc = 1 + 0.2√Kp Df/B; dq = dγ = 1 + 0.1√Kp Df/B
qu = c Nc sc dc + q Nq sq dq + ½ γ' B Nγ sγ dγ
AS 2159 / AS 4678 apply limit-state geotechnical reduction factors; FS shown for preliminary sizing.

Pad footing — Square pad: bearing, flexural steel, one-way shear and punching shear.
Spread footing from CPT: bearing and settlement — Pad or strip footing designed directly from a CPT, as in GEO5 Spread Footing CPT. The equivalent cone…
Strip footing with eccentric load — Strip footing under a wall with moment: eccentricity, effective width B′, trapezoidal pressure and ultimate…
Combined footing (two columns) — Length placing the resultant at the centroid (uniform pressure), width for allowable bearing, and maximum…
Strap (cantilever) footing — Exterior footing eccentric to a boundary column connected by a strap to an interior footing: reactions…
Footing uplift resistance — Uplift capacity from footing self-weight plus the soil frustum spreading at angle α, against wind uplift.

For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.