How this site is built
Review the calculation methodology to see which figures are exact geometry, which depend on material assumptions, and which figures have recorded sources. The source registry records every cited figure and its review status.
How the retaining wall block calculator works
This is a face-block count: wall face area divided by the exposed face module, with a cut allowance and whole-unit rounding.
It does not choose a wall system, embedment, batter, drainage, reinforcement or maximum height. Those are system and design decisions.
Formula used for retaining wall block calculator
The calculator keeps the measured quantity separate from any purchase rounding or allowance.
- Wall face
length × visible height - Block module
(face width + joint) × (face height + joint) - Count
face area ÷ module area × allowance
Planning choices for retaining wall block calculator
| Situation | Use | Why it matters |
|---|---|---|
| Low landscape wall | Face-block estimate | Useful for early material planning |
| Caps and corners | Count separately | They are different purchasable units |
| Engineered or tall wall | Use approved design | Quantity math cannot establish stability |
These are measurement and ordering choices, not structural specifications or code requirements.
Measure and order retaining wall block
Use exposed face dimensions, not pallet dimensions. Include buried courses only if they are part of the block count you intend to buy.
Confirm corner, cap and half-unit availability before finalizing a layout. Drainage aggregate is a separate volume.
Retaining Wall Block Calculator questions
Does wall height include the buried course?
Enter every course you need to purchase, including embedded units if the selected system requires them.
Are caps included?
No. Count cap units from the top run and the cap’s actual coverage.
Can this tell me how high I can build?
No. Follow the wall-system instructions and local requirements, and obtain engineering where required.
Variables and units
For the default “Wall face” mode. Other modes label their own fields in the calculator.
length- Wall length: ft, in, yd, m, cm.
height- Wall height: ft, in, yd, m, cm.
faceWidth- Exposed unit width: in.
faceHeight- Exposed unit height: in.
joint- Joint thickness: in.
waste- Cuts and breakage allowance: %; optional.
Worked example: a 30 ft by 3 ft garden wall
A garden wall is 30 ft long and 3 ft high, using a 16 in by 6 in exposed block face with no joint and 5% cuts.
| Field | Value |
|---|---|
| Wall length | 30 ft |
| Wall height | 3 ft |
| Exposed unit width | 16 in |
| Exposed unit height | 6 in |
| Joint thickness | 0 in |
| Cuts and breakage allowance | 5 % |
| Result | Value |
|---|---|
| blocks to buy | 142 blocks |
| Wall face area | 90 ft² |
These figures are generated by the same calculation the calculator above uses, so they update automatically if the method changes.
Where these numbers come from
| Assumption | Value used |
|---|---|
| Default mortar joint thickness.Joint thickness changes a brick count by roughly a fifth, so it is a required input rather than a hidden default. Measure an existing course or take the joint from your project specification. Applicability: Launch-market starting value only. A future market must supply reviewed regional or product-specific provenance before overriding it. You can replace this with your own figure. | 0.375 in |
Sources
- ASTM C216, Standard Specification for Facing Brick: ASTM International
Content release:
Published by Material Totals. Review the methodology and source assumptions.
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