Retaining Wall Calculator — Blocks, Drainage & Footing
Build a fast retaining wall material list from wall length, height, block size, and batter. The calculator flags walls over 4 feet so you can route them for engineering review.
Drainage planning rule
This calculator uses 1 cubic yard of drainage gravel per 10 square feet of wall face as a conservative planning allowance for free-draining backfill and chimney drain zones.
Footing assumption
The footing trench estimate assumes a trench width equal to block depth + 6 inches and a trench depth equal to block height + 6 inches. Adjust to match your detail and buried base course.
Frequently Asked Questions
Why does wall height change the number of courses?
Courses are calculated from total wall height divided by block height, rounded up so you have enough full courses to cover the rise.
What are deadman or batter blocks?
They are extra units used for reinforcement, tie-backs, returns, or extra interlock depending on the wall system and manufacturer detail.
Does this replace an engineered retaining wall design?
No. Use it for estimating only. Tall walls, surcharge loads, and poor soils need engineered design and local code review.
Keep the project moving
Use the free calculator for fast takeoffs, then plug the result into a reusable field template.
Need templates? Browse our professional template store — contracts, checklists, and planners from $17.