Calculate blocks, base aggregate and geogrid for a segmental retaining wall.
The first course is buried, so the block count always exceeds what the exposed height suggests. Walls above about 1.2 m generally need geogrid reinforcement and often engineering sign-off. Retaining wall failures are usually drainage or reinforcement failures rather than block failures, and height thresholds for engineering approval exist for exactly that reason.
Retaining Wall
Blocks = blocks per course × (exposed courses + one buried course)
Blocks = blocks per course × (exposed courses + one buried course) The first course is buried, so the block count always exceeds what the exposed height suggests. Walls above about 1.2 m generally need geogrid reinforcement and often engineering sign-off.
Retaining wall failures are usually drainage or reinforcement failures rather than block failures, and height thresholds for engineering approval exist for exactly that reason.
This calculator takes 5 inputs: Wall length, Exposed wall height, Block length, Block height, Base aggregate depth. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.