Block retaining wall calculator
Block, caps, a gravel pad, drainage stone, pipe and fabric for a segmental retaining wall up to about 4 ft, from its length and height.
An estimate of the materials a job takes, worked out in your browser: check it against the job, and against your local code where it matters. Nothing you type leaves this page.
Put in the job's numbers and choices, and the list below follows them.
What it takes
Worked out for Wall length 40 ft, Exposed height 3 ft, Block: 18 x 6 in face.
Wall
- Retaining wall block, 18 x 6 in 199 each Courses, one buried 7 each × Blocks a course 27 each: 189 each; plus 5% waste: 198.45; rounded up to whole each: 199. Taller than about 4 ft, a wall wants an engineer's design and often a permit: check local code.
- Retaining wall cap, 12 in 42 each Wall length 40 ft: 40 each; plus 5% waste: 42.
- Masonry adhesive 4 tube Wall length 40 ft, one per 10: 4 tube.
Base and drainage
- Crushed gravel base 2 cu yd ((Wall length 40 ft × 2) × 0.5) ÷ 27: 1.48 cu yd; plus 10% waste: 1.63; rounded up to whole cu yd: 2. A pad 24 in wide and 6 in deep.
- Drainage gravel, 3/4 in 5 cu yd (Wall length 40 ft × Exposed height 3 ft) ÷ 27: 4.44 cu yd; plus 10% waste: 4.88; rounded up to whole cu yd: 5. A foot of clean stone behind the wall.
- Perforated drain pipe, 4 in x 10 ft 5 each Wall length 40 ft at 10 a piece: 4 each; plus 10% waste: 4.4; rounded up to whole each: 5.
- Geotextile fabric, 4 x 50 ft roll 1 roll (Wall length 40 ft × (Exposed height 3 ft + 2)) ÷ 200: 1 roll.
Labor
- Retaining wall installation 120 sq ft Wall length 40 ft × Exposed height 3 ft: 120 sq ft.
What it leaves out
- Engineering for a wall over 4 ft
- Geogrid
- Permits and inspection fees
The same calculator in SMG Tools
In SMG Tools this calculator fills its numbers from the client's site measurements, prices every line from your own Price Book, checks the margin against your target, and carries the lines onto the proposal, the job's plan and the purchase order. It is one of the ready-made calculators SMG Tools sets up for concrete and hardscape, and calculators are on every plan.