Garden SurveyorRetaining Wall Calculator
Sleepers, blocks or gabions with drainage gravel and membrane.
Inputs
3 advanced inputs hidden. Switch to Advanced to fine-tune.
Confidencehigh· 75Complexitymedium· 34
- Wall length
- 5m
- Wall height
- 600mm
- Sleepers
- 7
- Posts
- 6
- Drainage gravel
- 2.25t
- Geotextile membrane
- 4m²
Heads-up: Drainage behind the wall is not optional: a perforated land drain wrapped in geotextile and backfilled with 20 mm clean stone, exiting to daylight or a soakaway. Why it matters: Without drainage, hydrostatic pressure builds behind the wall and pushes it over within a few winters.
This app provides general UK guidance and material estimates only. It is not legal, planning, engineering or building-control advice. Always confirm requirements with your local planning authority, building control, utility providers, manufacturers or qualified professionals.