Calculated result
114blocks
Blocks to order
Formula
MAS-SRW-001blocks = ceil(length × height ÷ (block length × block height) × (1 + waste))
96 ft²
Face area
108 blocks
Base block quantity
Masonry calculator
Retaining wall block calculator
Default example (24 ft wall length, 4 ft exposed height, 16 in block length, 8 in block height, 5% waste factor): Blocks to order is 114 blocks. In metric, face area is 8.92 m².
Formula. blocks = ceil(length × height ÷ (block length × block height) × (1 + waste))
SRW and garden-block count from exposed face area and the selected block face.
By Feroz Sheikh · Formula MAS-SRW-001 v1.0.0 · Tested formula
Formula
MAS-SRW-001v1.0.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Refine measurements and rates at any time. Your current values are included in the material-list PDF.
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
This calculator divides exposed retaining-wall face area by the selected block face, then applies a visible cutting allowance.
- Measure exposed length and height, not buried base course.
- Enter the actual block face, not a generic 8×16 if you are buying a different unit.
- Add caps, geogrid and drainage stone as separate estimate lines.
Add your project costs
Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.
Costs use the block, brick or mortar rate you type. Construclytic does not fetch masonry prices. Lintels, corners and labour stay separate estimate lines.
How this calculator works
A transparent retaining wall block takeoff.
Feroz SheikhWritten and reviewed by Feroz Sheikh · founder
This calculator divides exposed retaining-wall face area by the selected block face, then applies a visible cutting allowance.
MAS-SRW-001 counts SRW and garden blocks from exposed face area and the selected block face. Geogrid, drainage and heel volume are not in this count. It is a face takeoff, not a wall design.
Worked example. Example: a 24 ft × 4 ft exposed face using 16 in × 8 in blocks is 108 blocks before 5% waste, rounding to 114.
See the example inputs and calculated result
This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.
| Input | Example value |
|---|---|
| Wall length | 24 ft |
| Exposed height | 4 ft |
| Block length | 16 in |
| Block height | 8 in |
| Waste factor | 5 % |
Example result: Blocks to order — 114 blocks.
blocks = ceil(length × height ÷ (block length × block height) × (1 + waste))
Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.
- 1. Measure exposed length and height, not buried base course.
- 2. Enter the actual block face, not a generic 8×16 if you are buying a different unit.
- 3. Add caps, geogrid and drainage stone as separate estimate lines.
Field notes that change the number
- Use the exposed face you will see, including buried courses if they are in the order.
- Caps and corners are extras.
- A 6 in garden block is not an 8 in SRW unit.
Common mistakes
- Using CMU 8×16 on a landscaping block.
- Hiding geogrid inside the block count.
- Calling this a stamped retaining-wall design.
Need the broader workflow? Read the masonry planning guide.
How-to: How to count CMU and brick
Questions
Questions about retaining wall block
Does this design the wall?
No. Setback, geogrid, drainage, surcharge and local requirements need independent review.
Is the buried course included?
No. Add one extra course if the base is buried, or raise the height input.
What is the formula ID?
This retaining wall block calculator publishes formula MAS-SRW-001, version 1.0.0. The ID stays on the result and on the estimate line.