Retaining Wall Block Calculator
Segmental (SRW) blocks, cap units and gravel backfill for a garden wall.
Bury the first course (1/10th of height), step the wall back ~10°, and give water a way out — retaining walls die of hydrostatic pressure, not of soil.
Formula
Retaining Wall Block Calculator is a free retaining wall blocks for civil engineers, contractors and quantity surveyors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Retaining Wall Block Calculator
Segmental (SRW) blocks, cap units and gravel backfill for a garden wall. The calculation implements rows × blocks-per-row; gravel = L×H×0.3 m zone (NCMA SRW design manual). Bury the first course (1/10th of height), step the wall back ~10°, and give water a way out — retaining walls die of hydrostatic pressure, not of soil.
How to use Retaining Wall Block Calculator
- 1Enter Wall length in m.
- 2Enter Wall height in m (> 1.2 m usually needs engineering/permits).
- 3Enter Block face length in mm.
- 4Enter Block height in mm.
- 5Read Wall blocks, Cap units, Drainage gravel (300 mm zone) instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Retaining Wall Block Calculator?
- ✓Implements the standard formula — rows × blocks-per-row; gravel = L×H×0.3 m zone
- ✓Reference cited on-page: NCMA SRW design manual
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Retaining Wall Block Calculator use?+
It computes rows × blocks-per-row; gravel = L×H×0.3 m zone, per NCMA SRW design manual. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Bury the first course (1/10th of height), step the wall back ~10°, and give water a way out — retaining walls die of hydrostatic pressure, not of soil.
Does it include wastage?+
Yes — standard wastage/bulking factors are built in and stated in the formula line, so the quantity is an orderable number, not a bare geometric volume.
Is the Retaining Wall Block Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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