Retaining Wall Cap Calculator
Cap blocks and adhesive for a wall top.
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ⓘ Live results
Results
- Cap blocks needed
- 44
- Adhesive tubes (~8 caps/tube)
- 6
Quick answer
Cap block count is the wall length divided by the exposed length of each cap block, plus waste.
caps = ceil(length / cap length x (1+waste%))
How to use the Retaining Wall Cap Calculator
- 1Measure the total top length of the retaining wall.
- 2Enter the exposed length of your cap block style.
- 3Add 10% waste for curves and cuts, and adhesive to glue each cap down.
Worked example
Using the values the calculator loads with:
Inputs
- Wall length40 ft
- Cap block length12 in
- Waste allowance10 %
Results
- Cap blocks needed44
- Adhesive tubes (~8 caps/tube)6
Frequently asked questions
Do cap blocks need glue?
Yes, construction adhesive rated for masonry keeps caps from shifting or being knocked loose.
Can I use flagstone instead?
Yes, but calculate flagstone area instead of a linear cap block count.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.