From measured space to purchasable material
A modular landscape wall is easier to count course by course than by using face area alone. This calculator rounds the required exposed height to full courses, adds buried courses and counts the blocks needed across each course. Caps are estimated with their own length. It is a purchasing tool for a layout that has already been specified, and it does not determine whether a retaining wall is safe. Soil pressures, drainage, geogrid, setbacks, curves, foundations and applicable approvals require appropriate project-specific design.
Measure, select yield and round the order
- Use the wall geometry and buried courses from the project specification.
- Count complete block courses and top caps separately.
- Confirm special units and the engineered system’s bill of materials.
Net requirement and purchase calculation
A worked example
A 24 ft straight wall with 24 in exposed height, 6 in courses and 1 buried course has 5 courses. At 12 in block length and 5% spares, purchase 126 blocks and 26 caps.
Retaining Wall Block: what changes the result?
Compare the layer or product assumptions behind the material order. The comparisons below are calculated from this page’s default example. Each row changes only the named input; all other inputs stay at their displayed example values. These are mathematical scenarios, not measurements from a completed project.
| Changed assumption | Default input | Comparison input | Result: default → comparison |
|---|---|---|---|
| Wall run length | 24 ft | 28.8 ft | Blocks per straight course: 24 → 29 Wall blocks with allowance: 126 → 153 |
| Required exposed height | 24 in | 28.8 in | Total courses including buried: 5 → 6 Wall blocks with allowance: 126 → 152 |
| Block face length | 12 in | 14.4 in | Blocks per straight course: 24 → 20 Wall blocks with allowance: 126 → 105 |
| Additional buried courses | 1 | 2 | Total courses including buried: 5 → 6 Wall blocks with allowance: 126 → 152 |
Displayed values are rounded. Whole-pack results change in steps; continuous quantities may change before a new pack is needed. To compare your actual project, enter your dimensions above, save a scenario, then change one assumption.
Coverage, allowance and purchasing limits
- This calculator does not assess wall height limits, overturning, sliding or bearing.
- Curved layouts can change the front and back coverage of tapered blocks.
- Corners, ends, step-downs and geogrid connections need a detailed layout.
Frequently asked questions
Does the count include buried blocks?
Yes. Enter additional buried courses and they are added to the rounded exposed course count.
Are wall caps counted separately?
Yes. Cap length can differ from the wall block length.
Can this tell me whether my wall needs engineering?
No. Check project conditions and local requirements with the appropriate professional or authority.
Calculation method: JICWH methodology. Examples are planning assumptions, not product recommendations.