Calculated result
1.75yd³
Grout order
Formula
MAS-FIL-001ceil(L ÷ block length) × ceil(H ÷ block height) × grout per block × (1 + waste)
180 blocks
Blocks in the wall
45 ft³
Net grout volume
Masonry calculator
CMU grout fill calculator
a 20 × 8 ft wall of 16×8 in block is 180 units. At 0.25 ft³ of grout each, 5% waste rounds the grout order to 1.75 yd³. In metric, net grout volume is 1.27 m³.
Formula. ceil(L ÷ block length) × ceil(H ÷ block height) × grout per block × (1 + waste)
Grout volume and 80 lb bag equivalent to fill CMU cores from wall face, block module and grout per block.
By Feroz Sheikh · Formula MAS-FIL-001 v1.0.0 · Tested formula
Formula
MAS-FIL-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.
Bag table · waste in
Counts round up. A cubic yard is 45 of 80 lb, 60 of 60 lb, 72 of 50 lb, 90 of 40 lb.
| Bag | Count |
|---|---|
| 80 lb | 79 |
Count CMU units from wall face and the block module, multiply by the grout volume of one fully grouted block, then round ready-mix to the next 0.25 yd³ and show an 80 lb bag equivalent.
- Measure the wall that will actually be grouted, not the whole building.
- Enter grout per block from the unit you are laying. 8 in and 12 in cores are not the same.
- Bond beams, lintels and partial-height grout are extra. This tool is a full-height core fill.
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 cmu grout fill takeoff.
Feroz SheikhWritten and reviewed by Feroz Sheikh · founder
Count CMU units from wall face and the block module, multiply by the grout volume of one fully grouted block, then round ready-mix to the next 0.25 yd³ and show an 80 lb bag equivalent.
MAS-FIL-001 is grout volume to fill CMU cores from wall face, block module and a grout-per-block yield, then 80 lb bags. Laying mortar is a different calculator. It is not a structural grout design.
Core grout is not laying mortar
Keep core fill off the mortar line. Joint mortar for hollow and solid block is in mortar for a block wall per square metre.
Worked example. Example: a 20 × 8 ft wall of 16×8 in block is 180 units. At 0.25 ft³ of grout each, 5% waste rounds the grout order to 1.75 yd³.
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 | 20 ft |
| Wall height | 8 ft |
| Block length | 16 in |
| Block height | 8 in |
| Grout per block | 0.25 ft³ / block |
| Waste factor | 5 % |
Example result: Grout order — 1.75 yd³.
ceil(L ÷ block length) × ceil(H ÷ block height) × grout per block × (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 the wall that will actually be grouted, not the whole building.
- 2. Enter grout per block from the unit you are laying. 8 in and 12 in cores are not the same.
- 3. Bond beams, lintels and partial-height grout are extra. This tool is a full-height core fill.
Field notes that change the number
- Fully grouted and every-other-core are different yields — change the input.
- Bond beams and lintels are extra prisms.
- Fine and coarse grout do not share a bag yield.
Common mistakes
- Using laying-mortar bags as grout fill.
- Ignoring cells you will not fill.
- Calling this a seismic design.
Need the broader workflow? Read the masonry planning guide.
Questions
Questions about cmu grout fill
Is 0.25 ft³ right for every 8 in block?
It is a common fully grouted two-core planning figure, not a catalog value. Read the block data sheet when the pour is large.
Every other core?
If you grout cells at 16 or 32 in on center, lower grout per block to match the cells you will fill, or run the wall in sections.
What is the formula ID?
This cmu grout fill calculator publishes formula MAS-FIL-001, version 1.0.0. The ID stays on the result and on the estimate line.