What this calculator does
Retaining wall blocks works out number of retaining wall blocks for a wall from its length, height and block size. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formularows = ⌈wall height / block height⌉; columns = ⌈wall length / block length⌉; blocks = rows × columns
The inputs explained
| Field | What to enter |
|---|---|
| Wall length (m) | A number, measured in m. Starts at 6. |
| Wall height (m) | A number, measured in m. Starts at 0.6. |
| Block length (cm) | A number, measured in cm. Starts at 40. |
| Block height (cm) | A number, measured in cm. Starts at 20. |
| Waste allowance (%) | A number, measured in %. Starts at 5. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with wall length
Every other input is held at the calculator’s starting values while wall length varies. Select any row to load that scenario into the calculator.