SettingsSettings for this calculationUS
The total number of vertical cells being grouted.
Count individual cell locations, e.g. every cell, every other cell, or only cells with vertical rebar, depending on your design.
The cross-sectional area of one cell void, from the manufacturer's spec sheet.
A standard 8x8x16 in CMU cell is commonly around 28-32 in² depending on web thickness.
The full height of grout pour (the vertical extent of the grouted cells).
The height of the GROUT, not of the wall. A wall grouted only where the vertical bars run, from footing to bond beam, has a grout height that stops where the beam starts; a wall grouted in lifts has several heights, each its own pour. Where cells are filled low and dowelled higher, only the filled part counts — entering the wall height instead is the commonest reason a grout order comes back a third too large.
Grout volume needed
33.3 ft³
Uses the manufacturer's cell area directly — actual grout consumption is somewhat less than the raw cell void due to mortar protrusions into the cell from the bed/head joints, typically accounted for with a small waste allowance when ordering.
- Grout per cell (full height)
- 12.47 gal
- Cubic yards
- 1.23 yd³
They open the calculator with your figures already in it
CMU Cell Grout Volume Calculator: 33.33 ft³ — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Grout volume = number of grouted cells x cell cross-sectional area x wall height, for vertically continuous grouted cores
Inputs used
- Number of Grouted Cells
- 20
- Cell Cross-Section Area
- 30 in²
- Wall Height
- 8 ft
Intermediate steps
- Grout per cell (full height)
- 12.47 gal
- Cubic yards
- 1.23 yd³
Confidence note: Uses the manufacturer's cell area directly — actual grout consumption is somewhat less than the raw cell void due to mortar protrusions into the cell from the bed/head joints, typically accounted for with a small waste allowance when ordering.
What this calculation does not cover
- Vertical cells only. Bond beam courses and lintel units carry grout horizontally and are measured as a channel cross-section times the run, while grouted pilasters and columns run vertically but on a far larger cross-section than one cell area. None of that volume appears here, and bond beam grout is the line most often left off a grout order.
- This is the theoretical void, with nothing added or taken off. It excludes spillage, pump and line loss, over-pour, grout escaping through unmortared cross webs or open head joints, and grout that runs away down ungrouted cells under a bond beam that has not been dammed. Any ordering allowance goes on top of this number.
- One cell area is applied to every cell over the whole height. It does not account for variation between unit types in the same wall, half and corner units, or the mortar squeezed off the bed joints that protrudes into the cell and reduces what that cell actually takes.
- It is not a structural or code check. It does not decide which cells must be grouted, and it verifies nothing about clear grout space, fine versus coarse grout, aggregate or bar size, the pour and lift height limits masonry codes impose, or whether cleanouts are required at the base of the grouted cells. Take all of that from the drawings and the specification.
- The cell count is taken on trust. Nothing here derives it from wall length, unit size or bar spacing, so a cell miscounted off the reinforcement schedule passes straight through into the volume with no cross-check.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.1.1
Regulatory standards & verification citations1
- Grout volume = number of grouted cells x cell cross-sectional area x wall height, for vertically continuous grouted cores
Cite this page
Your workspace
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Tools and safety for this job
To lay block and mix mortar. Generic types, no brands, no prices.
Protection this work requires
- Cutting or grinding concrete, masonry, screed, tile or fibre-cement board releases respirable silica: cut wet or extract at the tool, and wear a P2/N95 respirator at minimum — a nuisance dust mask does not filter it.
- Wet cement and lime burn skin and eyes painlessly until the damage is done: waterproof gloves to EN 374, safety glasses whenever the mix can splash, and never kneel in wet mix in permeable trousers.
- Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
Show the 8 tools this job needsHide tools
Essential
Brick trowel and jointer
Shovel and spade
Spirit level
String line and pins
Wheelbarrow
Recommended
Block splitter
Cement mixer
Mixing bucket or tub
what each masonry tool is for, and the spec that decides which to buy where one does.