Retaining wall block calculator
Count retaining-wall blocks and base gravel from the length and height you type.
Result
Retaining wall block calculator
- Units (required)
- Feet and inches
Blocks
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Enter the wall size, the block size, and the base width and depth.
Ballpark estimate, check before you buy or quote.
Verify with your local code or a professional.
Estimate for planning only. This is not tax, legal, accounting or financial advice. Results depend on the figures you enter. Check all numbers, rates and rules with the official source or a qualified professional before relying on them.
How this works and common questions
About this tool
Courses are the height divided by the block height, rounded up. Blocks along the wall are the length divided by the block length, rounded up. Gravel is the trench you type.
How it works
Courses round up from the wall height divided by the block height. Blocks in one course round up from the wall length divided by the block length. The block count is those two numbers multiplied, then the waste percent rounds up. Gravel is length times base width times base depth, without that waste.
Rules
This is not a structural design. Verify with your local code or a professional. Ballpark estimate, check before you buy or quote.
Questions
How many blocks?
The height divided by the block height, rounded up, times the length divided by the block length, rounded up.
How is the gravel found?
Length times the base width times the base depth you type. Waste is not added to the gravel.
What is the example?
A 20 foot wall, 3 feet high, with 12 by 6 inch blocks is 6 courses of 20, which is 120 blocks. A base 24 inches wide and 6 inches deep is 0.741 cubic yards.
Do I need an account?
No. The tools work without one. You only need to sign in to save your work.
Is what I type saved?
No. Nothing is saved unless you sign in and choose Save. Otherwise it stays on the page.
Do you show ads or sell my information?
No. We show no ads and we do not sell your information.
Is this tax or legal advice?
No. Results are estimates for planning. Check rates and rules with the official source or a qualified professional.
Sign in to save this. Your entries stay on screen.
Estimate for planning only. This is not tax, legal, accounting or financial advice. Results depend on the figures you enter. Check all numbers, rates and rules with the official source or a qualified professional before relying on them.