Retaining Wall Calculator
Estimate retaining-wall blocks, rows, cap units, pallets, face area and material cost from wall dimensions and block size.
Default project preview
335 wall blocks
Courses
10
Blocks per course
31
Full pallets
5
Cap blocks
31
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Wall length
Enter this project assumption in ft. The current imperial default is 30 ft.
Wall height
Enter this project assumption in ft. The current imperial default is 3 ft.
Block face length
Enter this project assumption in in. The current imperial default is 12 in.
Block face height
Enter this project assumption in in. The current imperial default is 4 in.
Waste allowance
Enter this project assumption in %. The current imperial default is 8 %. Minimum: 0. Maximum: 50.
Blocks per pallet
Enter this project assumption in a unitless value. The current imperial default is 72.
Price per wall block
Enter this project assumption in a unitless value. The current imperial default is 4.25. Minimum: 0.
Price per cap block
Enter this project assumption in a unitless value. The current imperial default is 5. Minimum: 0.
How to read the outputs
Courses
rounded vertical rows. Default preview: 10.
Blocks per course
before cuts. Default preview: 31.
Full pallets
72 blocks each. Default preview: 5.
Cap blocks
one top course. Default preview: 31.
Wall face area
visible face. Default preview: 90 ft².
Material cost
blocks and caps. Default preview: $1,578.75.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Courses = round up (wall height ÷ block height). Blocks per course = round up (wall length ÷ block length). Order blocks = courses × blocks per course × waste factor.
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 29, 2026
This calculator estimates retaining-wall units, cap units, base aggregate and drainage stone from wall dimensions and product coverage. It is a quantity tool only; wall stability, reinforcement and drainage design are project-specific.
Calculation steps
- 1Measure wall length and average exposed height.
- 2Use the exact block face coverage.
- 3Add buried courses if they are part of the product layout.
- 4Estimate cap, base and drainage materials separately.
Worked numerical example
A 30 ft wall averaging 3 ft high has 90 ft² of face area. If one block covers 0.67 ft², the base count is about 135 blocks before cuts and waste.
Purchasing and rounding
Wall blocks and caps are purchased as whole units or pallets. Corner blocks, curves and color blending can require additional quantities.
Interpret the result
Face-area quantity does not establish whether the wall can resist soil and water loads. Taller or surcharged walls may require engineered design.
Page-specific assumptions
- Uniform block system.
- Average wall height is representative.
- Simple straight alignment unless curves are separately measured.
- Drainage and reinforced soil zones use entered dimensions.
Common mistakes
- Ignoring buried base courses.
- Using nominal block dimensions instead of face coverage.
- Omitting drainage stone.
- Treating wall height as the only design variable.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Retaining Wall Calculator questions
Should buried blocks be included?+
Yes when required by the wall system. Increase the entered height to include buried courses.
When is geogrid required?+
Requirements depend on wall height, soil, slope and loads. Follow the block-system design tables and local engineering requirements.
Does this calculate drainage gravel?+
No. Drainage stone and base material depend on the manufacturer detail and site conditions.