Work out retaining wall stability instantly with clear inputs, formula shown and shareable results.
A gravity retaining wall is checked against two failure modes. Overturning compares the restoring moment of the wall's own weight about the toe with the moment of the active thrust, which acts at one third of the height for the soil triangle and mid-height for the surcharge rectangle. Sliding compares base friction, taken here at a coefficient of 0.5, with the horizontal thrust.
Active thrust
Pa = 0.5 Ka gamma H² + Ka q H per metre of wall
Stability
FoS overturning = W x B/2 / (Pa moment); FoS sliding = 0.5 W / Pa
Preliminary estimate only. Retaining wall design must be carried out by a qualified engineer including drainage, bearing capacity, global stability and reinforcement design.
Pa = 0.5 Ka gamma H² + Ka q H per metre of wall. A gravity retaining wall is checked against two failure modes.
Typically 2.0 against overturning and 1.5 against sliding, with bearing pressure inside the allowable value and the resultant kept within the middle third of the base.
This calculator takes 4 inputs: Wall height, Base width, Surcharge on retained soil, Active earth pressure coefficient. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.