Concrete Grout Fill Calculator (USA)
✓ 100% Free
Concrete Grout Fill
Calculator USA — CMU Walls, Bags & Cost
Instantly calculate masonry grout fill volume in cubic feet, bags, and total material cost for CMU block walls, hollow concrete block cells, bond beams, masonry columns, and partially grouted walls — ASTM C476 & ACI 530 / TMS 402 compliant.
2,000
Min. PSI — ASTM C476 Fine Grout
48 in
Max. Grout Pour Height (Low Lift)
10%
Standard Waste Factor for CMU Grout
80 lb
Standard Masonry Grout Bag Size
🧱 CMU Block Wall
🏛️ Masonry Column
🔗 Bond Beam
🏗️ Partially Grouted Wall
🪟 Lintel / Opening Fill
🏠 Retaining Wall
A concrete grout fill calculator for the USA helps masonry contractors, structural engineers, general contractors, and homeowners determine the exact grout fill volume in cubic feet, number of 80-lb bags, and total material cost for filling CMU (concrete masonry unit) block walls, hollow block cells, masonry columns, bond beams, and lintels. Masonry grout fill per ASTM C476 is a flowable cementitious mixture — either fine grout (Portland cement + fine aggregate) or coarse grout (Portland cement + fine + coarse aggregate) — used to fill the hollow cores of CMU and brick masonry walls to create a solid, reinforced composite assembly. Fully grouted CMU walls are required for structural, seismic, and high-wind applications per ACI 530 / TMS 402. Whether you are filling every cell, every other cell, or only bond beam courses, this free tool calculates net grout volume, bags needed, waste overage, and total cost using current 2025 US pricing.
🧱 Concrete Grout Fill Calculator — USA
🇺🇸 Free Tool · ASTM C476 · ACI 530 · TMS 402 · USA
Grout Fill Calculator
Calculate CMU grout fill volume, cubic feet, bags & cost for any masonry wall or column
🧱 CMU Wall
🏛️ Column
🔗 Bond Beam
🏗️ Partial Fill
🪟 Lintel
Select your CMU block size, wall dimensions, grout spacing, and bag price for a complete fill estimate.
All cells filled — required for seismic, high-wind & structural walls per TMS 402.
8×8×16 in is the most common US CMU block — 2 cores per block, each ~5×5 in.
Total wall length along the face of the CMU wall.
Standard 8-in CMU wall: 8 ft = 12 courses. Each course = 8 in height.
Hollow core width inside CMU block. Standard 8-in CMU: ~5 in wide per core.
Core depth (in wall thickness direction). Standard 8-in CMU: ~5 in deep.
Standard 8×8×16 CMU has 2 hollow cores per block.
Fully grouted = every cell. Partial grouting fills only cells with vertical rebar.
Fine grout required when smallest cell dimension is under 3 in. Most 8-in CMU = fine grout.
2025 USA avg: $9–$16 per 80-lb bag (ASTM C476 masonry grout). Ready-mix also available.
Check manufacturer data sheet. ~0.45 cu ft per 80-lb bag is typical for fine masonry grout.
Total Masonry Grout Fill Required
—
80-lb bags including waste factor
📋 Grout Fill Summary
💵 Estimated Material Cost
🧱 CMU Grout Fill Cross-Section — Fully Grouted, Partially Grouted & Bond Beam (USA)
0.45
Cu Ft Yield Per 80-lb Grout Bag
2,000
Min. PSI — ASTM C476 Fine Grout
48 in
Max. Low-Lift Grout Pour Height
Grout Fill (ASTM C476)
CMU Block Shell
Empty / Ungrouted Cell
Vertical / Horizontal Rebar
Bond Beam Block
What Is Masonry Grout Fill & When Is It Required in the USA?
Masonry grout fill per ASTM C476 is a high-slump cementitious mixture pumped or poured into the hollow cores of CMU (concrete masonry unit) block walls, masonry columns, and bond beam courses to create a solid, reinforced composite wall assembly. Unlike standard concrete, masonry grout is designed to be extremely fluid (8–11-inch slump) so it flows freely around vertical rebar and completely fills the narrow cells of CMU blocks without vibration. ASTM C476 defines two types: fine grout (portland cement + sand; used when any cell dimension is under 3 inches — applies to most 8-inch CMU) and coarse grout (portland cement + sand + 3/8-inch pea gravel; used in larger cells ≥ 3 inches clear). Full grouting is required by ACI 530 / TMS 402 for seismic design categories D, E, and F, high-wind regions, and all structural masonry columns.
🔵 Fully Grouted vs. Partially Grouted CMU Walls — Key USA Code Differences
Fully grouted walls: Every cell filled — required for seismic categories D/E/F per TMS 402, all masonry columns, heavily loaded shear walls, and most commercial construction. Provides highest strength, mass, and fire rating. Partially grouted walls: Only cells containing vertical rebar are filled — commonly used in seismic categories A/B/C for residential and light commercial construction where full grouting is not code-required. Reduces material cost by 40–60% vs. full grouting. Bond beam grouting: Entire horizontal course filled with grout and continuous horizontal rebar — required at top of wall, at floor/roof diaphragm connections, and at regular intervals (typically every 4 ft vertically) to tie the wall together and distribute lateral loads.
🧱 Standard 8-inch CMU Grout Fill
The most common US CMU block — 8×8×16 inches — has two hollow cores each approximately 5×5 inches. Each block requires about 0.067 cu ft (116 cu in) of grout per core for a fully grouted wall (2 cores × 0.033 cu ft each). A standard 8-ft tall × 20-ft long wall (approximately 180 blocks) requires roughly 12–14 cubic feet of grout fill including 10% waste — about 27–32 bags of 80-lb masonry grout.
🔗 Bond Beam Grouting Requirements
Bond beams use special U-shaped or open-ended CMU blocks that allow continuous horizontal rebar to run the full length of the wall. The entire bond beam course is filled with ASTM C476 fine grout. TMS 402 requires bond beams at the top of every wall, at floor and roof connections, and typically at every 4 feet of wall height in seismic and high-wind applications. Bond beam grout volume equals the full wall length × block height (8 in) × wall width, minus the face shell thickness deduction.
🏛️ Masonry Column Grouting
Masonry columns — typically 16×16, 24×16, or 24×24 inches built from standard CMU — must have all cells fully grouted per TMS 402 Section 6. Corner rebar (typically 4 × #5 or #6 bars) runs vertically in the corner cells, with horizontal ties at 8–16 inch spacing. A single 8-course-tall (5.3 ft) masonry column 16×16 in requires approximately 3.5–4.5 cubic feet of grout — about 8–10 bags of 80-lb masonry grout.
How to Calculate Masonry Grout Fill Volume for CMU Walls
Masonry grout fill volume is calculated by determining the net void area of the cells to be filled (cell width × cell depth per course), then multiplying by the total height of filled cells and the number of cells per linear foot of wall. For partially grouted walls, multiply by the fraction of cells being filled (e.g., 0.5 for every other cell). Always add a 10% waste factor for spillage, block absorption, and minor variations in cell dimensions.
📐 Masonry Grout Fill Volume Calculation Formulas (USA — Imperial)
Cells per Linear Foot = 12 in ÷ Block Length (in) × Cells per Block
Cell Volume per LF per Course = Cell Width (in) × Cell Depth (in) × Block Height (in) ÷ 1,728
Net Grout Vol (cu ft) = Cell Vol/LF × Cells/LF × Wall Length (ft) × Wall Height (ft) ÷ Block Height (ft)
Partial Grout: Multiply Net Vol by Grout Spacing Factor (e.g. 0.5 for every other cell)
Total Vol with Waste = Net Vol (cu ft) × Waste Factor (e.g. 1.10)
Bags Required = Total Vol (cu ft) ÷ Yield per Bag (cu ft)
Example: 40 ft × 8 ft wall · 8-in CMU · fully grouted = ~13.3 cu ft = 33 bags (80-lb, 0.45 cu ft/bag + 10%)
⚠️ Always Use ASTM C476 Masonry Grout — Never Regular Concrete Mix in CMU Cells
Standard ready-mix concrete cannot be used to fill CMU cells — it is too stiff to flow freely around rebar and into narrow cell openings, and will leave voids that destroy the composite wall action. ASTM C476 masonry grout must achieve a slump of 8–11 inches (highly fluid) so it self-consolidates without vibration. The minimum water-cement ratio is higher than structural concrete — this is intentional, because the CMU block absorbs water during the pour, effectively lowering the final W/C ratio. Never add extra water to grout on site beyond the specified mix — this reduces compressive strength and can cause segregation and cell voids.
Masonry Grout Fill Volume by Wall Size — USA Reference Table
Quick-reference table for grout fill volume and bag count by wall size for standard 8×8×16 CMU blocks, fully grouted, with two 5×5-inch cores per block. All figures use a 10% waste factor, 0.45 cu ft/bag yield (80-lb ASTM C476 fine grout), and $12/bag average 2025 US pricing.
| Wall Size (L × H) | Block Count | Net Grout Vol (cu ft) | + 10% Waste | 80-lb Bags | Est. Material Cost |
|---|---|---|---|---|---|
| 10 ft × 8 ft | ~90 blocks | 3.3 cu ft | 3.6 cu ft | 8 bags | $96 |
| 20 ft × 8 ft | ~180 blocks | 6.6 cu ft | 7.3 cu ft | 17 bags | $204 |
| 40 ft × 8 ft | ~360 blocks | 13.3 cu ft | 14.6 cu ft | 33 bags | $396 |
| 40 ft × 12 ft | ~540 blocks | 20.0 cu ft | 22.0 cu ft | 49 bags | $588 |
| 60 ft × 10 ft | ~675 blocks | 24.9 cu ft | 27.4 cu ft | 61 bags | $732 |
| 100 ft × 12 ft | ~1,350 blocks | 50.0 cu ft | 55.0 cu ft | 123 bags | $1,476 |
| 200 ft × 16 ft (warehouse) | ~3,600 blocks | 133.3 cu ft | 146.6 cu ft | 326 bags | $3,912 |
20 ft × 8 ft Wall (8-in CMU, Full Grout)
Block Count~180 blocks
Net Grout Volume6.6 cu ft
+ 10% Waste7.3 cu ft
Bags (80-lb)17 bags
Material Cost$204
40 ft × 8 ft Wall (8-in CMU, Full Grout)
Block Count~360 blocks
Net Grout Volume13.3 cu ft
+ 10% Waste14.6 cu ft
Bags (80-lb)33 bags
Material Cost$396
60 ft × 10 ft Wall (8-in CMU, Full Grout)
Block Count~675 blocks
Net Grout Volume24.9 cu ft
+ 10% Waste27.4 cu ft
Bags (80-lb)61 bags
Material Cost$732
100 ft × 12 ft Wall (8-in CMU, Full Grout)
Block Count~1,350 blocks
Net Grout Volume50.0 cu ft
+ 10% Waste55.0 cu ft
Bags (80-lb)123 bags
Material Cost$1,476
Masonry Grout Specifications by CMU Wall Application — USA 2025
The table below summarizes ASTM C476 masonry grout type, minimum compressive strength, slump, pour method, and applicable US code standard for each common CMU wall application. Confirm grout type with the project’s structural engineer — the project specifications often call out specific grout type, slump, and lift height requirements on the masonry notes sheet.
| Application | Grout Type | Min. PSI | Slump | Lift Method | Standard |
|---|---|---|---|---|---|
| Fully Grouted CMU Wall (Residential) | Fine | 2,000 | 8–11 in | Low-lift ≤ 4 ft | TMS 402 / ACI 530 |
| Fully Grouted CMU Wall (Commercial) | Fine / Coarse | 2,000–3,000 | 8–11 in | High-lift ≤ 24 ft | TMS 402 / IBC 2021 |
| Partially Grouted CMU Wall | Fine | 2,000 | 8–11 in | Low-lift ≤ 4 ft | TMS 402 §7.3 |
| Bond Beam Course | Fine | 2,000 | 8–11 in | Pour per course | TMS 402 §6.1 |
| Masonry Column | Fine / Coarse | 2,000–3,000 | 8–11 in | High-lift w/ cleanouts | TMS 402 §6.2 |
| CMU Retaining Wall (Fully Grouted) | Fine / Coarse | 2,500–3,000 | 8–11 in | Low-lift ≤ 4 ft | TMS 402 / IBC 1807 |
| Lintel / Opening Fill | Fine | 2,000 | 8–11 in | Direct pour | ACI 530 / TMS 402 |
Fully Grouted CMU Wall (Residential)
Grout TypeFine
Min. PSI2,000
Slump8–11 in
Lift MethodLow-lift ≤ 4 ft
StandardTMS 402 / ACI 530
Fully Grouted CMU Wall (Commercial)
Grout TypeFine / Coarse
Min. PSI2,000–3,000
Slump8–11 in
Lift MethodHigh-lift ≤ 24 ft
StandardTMS 402 / IBC 2021
Masonry Column
Grout TypeFine / Coarse
Min. PSI2,000–3,000
Slump8–11 in
Lift MethodHigh-lift w/ cleanouts
StandardTMS 402 §6.2
CMU Retaining Wall
Grout TypeFine / Coarse
Min. PSI2,500–3,000
Slump8–11 in
Lift MethodLow-lift ≤ 4 ft
StandardTMS 402 / IBC 1807
CMU Grout Fill Placement Tips — USA Best Practices
Proper masonry grout placement technique is as important as using the correct ASTM C476 mix. The TMS 402/602 Masonry Code and Specification governs all grouting procedures in the USA. Always follow the specified pour height limits and consolidation requirements — grout poured in lifts that are too tall cannot be properly consolidated and will leave voids in the lower cells.
📏 Low-Lift vs. High-Lift Grouting
Low-lift grouting (≤ 48 inches per pour) is used for most residential and light commercial CMU construction — the wall is built to 4 ft, grouted, allowed to gain strength, then the next 4-ft lift is built and grouted. High-lift grouting (up to 24 ft in a single pour) is used on commercial and industrial projects where scaffold moves are minimized — it requires cleanout holes in the bottom course of each cell, inspection of cells before grouting, and mechanical consolidation by rodding or vibration every 18 inches of lift height per TMS 602.
🧹 Cell Cleaning Before Grouting
Before grouting, all cell interiors must be inspected and cleaned of mortar droppings, debris, and standing water. For high-lift grouting, cleanout holes (minimum 3 × 4 inches) must be cut into the bottom face shell of every cell to be grouted, cleaned out with compressed air and water, then inspected by the inspector before grouting. Mortar fins projecting more than 0.5 inches into cells must be removed per TMS 602 Section 3.5B — they obstruct grout flow and create voids around rebar.
💧 Consolidation & Reconsolidation
ASTM C476 masonry grout must be consolidated by rodding or mechanical vibration within 15 minutes of placement and then reconsolidated after initial settlement but before final set. For low-lift grouting, rod each cell at least 3 times after pouring each 4-ft lift. For high-lift grouting, use a small pencil vibrator (1–1.5 inch head) inserted every 18 inches of pour height. Do not vibrate within 18 inches of a previous grout stop (construction joint) to avoid disturbing the partially set grout below.
❓ Frequently Asked Questions — Concrete Grout Fill Calculator
How many bags of grout do I need to fill a CMU block wall?
+
Bag count depends on wall size, CMU block size, and whether you are doing full or partial grouting. For standard 8×8×16 CMU, fully grouted with 80-lb bags (0.45 cu ft/bag yield), typical requirements:
- 10 ft × 8 ft wall: ~8 bags
- 20 ft × 8 ft wall: ~17 bags
- 40 ft × 8 ft wall: ~33 bags
- 40 ft × 12 ft wall: ~49 bags
- 100 ft × 12 ft wall: ~123 bags
For larger projects, ordering ready-mix masonry grout by the cubic yard is more cost-effective than bagged grout. One cubic yard of masonry grout fills approximately 60 bags worth of wall. Use the calculator above for exact quantities for your specific dimensions and block size.
What is the difference between fine and coarse masonry grout?
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Per ASTM C476:
- Fine grout: Portland cement + fine aggregate (sand only) — maximum aggregate size 3/8 inch · used when any cell dimension is less than 3 inches · required for most standard 8-inch and 6-inch CMU · higher cement content = higher cost but better penetration into small cells
- Coarse grout: Portland cement + fine aggregate + coarse aggregate (maximum 3/8 inch pea gravel) · used when minimum cell dimension is ≥ 3 inches · applicable to 10-inch, 12-inch, and larger CMU · slightly lower cost per cubic foot than fine grout due to aggregate substitution
- Key rule: If there is any question about cell size, default to fine grout — using coarse grout in undersized cells causes aggregate bridging and voids
- Both types: Minimum 2,000 PSI compressive strength at 28 days · 8–11 inch slump · ASTM C476 certified
Do all CMU walls need to be fully grouted?
+
Not always — US building codes allow partial grouting in many situations:
- Seismic Design Categories A, B, C: Partial grouting is permitted — only cells with vertical rebar need to be filled
- Seismic Design Categories D, E, F: Full grouting typically required for structural masonry walls per TMS 402
- High-wind areas (ASCE 7 Exposure D): Engineer will often specify full grouting regardless of seismic category
- Masonry columns: Always fully grouted — no exceptions per TMS 402 §6.2
- Shear walls: Usually fully grouted for maximum in-plane stiffness and strength
- Non-structural partition walls: May be left ungrouted in low-seismic, low-wind areas
- Retaining walls: Almost always fully grouted due to soil pressure loading
Always confirm grouting requirements with the project structural engineer and local building department — requirements vary by state, county, and jurisdiction.
How much does masonry grout fill cost per block in the USA (2025)?
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2025 US pricing for ASTM C476 masonry grout fill:
- Bagged masonry grout (80-lb bag): $9–$16 per bag at big-box or masonry supply
- Ready-mix masonry grout (by truck): $140–$200 per cubic yard delivered
- Cost per standard 8×8×16 CMU block (fully grouted, bagged): $0.60–$1.10 per block (material only)
- Cost per sq ft of wall (fully grouted, material only): $0.55–$0.95 per sq ft
- Installed cost (material + labor): $1.50–$3.50 per sq ft of grouted wall
For large commercial projects (> 50 cu ft of grout), ready-mix masonry grout pumped by truck is far more cost-effective than bagged grout:
- 50 cu ft by bag: ~112 bags × $12 = $1,344 + labor to mix
- 50 cu ft by ready-mix: ~1.85 yd³ × $165 = $305 delivered + pump
What is the maximum grout pour height for CMU walls in the USA?
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Per TMS 602 (Specification for Masonry Structures) and ACI 530.1:
- Low-lift grouting: Maximum 48 inches (4 ft) per lift — wall is built in 4-ft sections, each grouted before building higher
- High-lift grouting: Maximum 12.67 ft (1 story) per lift without special inspection — requires cleanout holes, cell inspection, and mechanical consolidation every 18 inches
- High-lift with special inspection: Up to 24 ft per lift — requires engineer approval, cleanout holes in every cell, pre-grout inspection, and vibration consolidation
- Pour rate: Grout should not be poured faster than 5 ft per hour for high-lift to prevent blowout of face shells
- Construction joints: Grout must stop 1.5 inches below the top of the masonry at each lift to create a key for the next lift — never pour flush with mortar joints
Can I use ready-mix concrete instead of masonry grout to fill CMU cells?
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No — standard ready-mix concrete cannot be substituted for ASTM C476 masonry grout:
- Slump: Ready-mix concrete typically has 3–5 in slump — far too stiff to flow into narrow CMU cells. Masonry grout requires 8–11 in slump minimum
- Aggregate size: Standard ready-mix uses 3/4 in or 1 in aggregate — too large to pass through CMU cell openings around rebar. ASTM C476 grout uses maximum 3/8 in aggregate
- Code compliance: TMS 402 and IBC specifically require ASTM C476 grout for masonry cell fill — using standard concrete violates the specification and can void inspection approvals
- Exception: Some engineers specify structural concrete (ASTM C94) for very large masonry cell fills (10-in or 12-in CMU with large open cells) — but this must be explicitly approved on the structural drawings
- Ready-mix masonry grout: A specialty product ordered by cubic yard from ready-mix plants — this IS acceptable and cost-effective for large projects. Confirm it meets ASTM C476 on the delivery ticket
How do I calculate grout for a partially grouted CMU wall?
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For a partially grouted wall, calculate as follows:
- Step 1: Determine which cells are grouted — typically every cell containing a vertical rebar (e.g., #5 bar at 24 in o.c. = every 3rd cell of an 8-in CMU wall)
- Step 2: Calculate net volume per grouted cell = Cell Width × Cell Depth × Wall Height (in cubic feet)
- Step 3: Count total grouted cells = Wall Length ÷ Rebar Spacing × 1 cell per rebar location
- Step 4: Total Net Volume = Volume per cell × Number of grouted cells
- Step 5: Add waste factor (10%) and convert to bags
- Example: 40 ft wall · rebar at 24 in o.c. · 8-in CMU · 8 ft tall: 20 grouted cells × 0.167 cu ft each = 3.33 cu ft net · + 10% = 3.67 cu ft · ÷ 0.45 = 9 bags
This is about 27% of the 33 bags needed for the same wall fully grouted — significant material savings for non-seismic applications. Use the “Partially Grouted” option in the calculator above.
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📚 Official Standards & Industry Resources
Authoritative ASTM, TMS, ACI, and industry references for masonry grout fill in the USA
📋
ASTM C476 — Masonry Grout
ASTM Standard · USA
ASTM C476 is the standard specification for grout used in masonry construction in the USA — covering fine and coarse grout mix proportions, compressive strength requirements (minimum 2,000 PSI), aggregate gradation, slump, and testing methods for all CMU wall, masonry column, bond beam, and lintel fill applications.
TMS 402 — Masonry Building Code
TMS Standard · USA
TMS 402 / ACI 530 “Building Code Requirements and Specification for Masonry Structures” is the primary US masonry design code governing grouting requirements, grout lift heights, cleanout requirements, partial vs. full grouting specifications, masonry column design, and seismic grouting requirements for all CMU construction in the USA.
NCMA — CMU Technical Notes
Industry Resource · USA
The National Concrete Masonry Association (NCMA) publishes comprehensive Technical Bulletins covering CMU grout fill design, low-lift and high-lift grouting procedures, cleanout hole requirements, grout consolidation methods, and block grout volume tables for all standard CMU sizes used in US construction.
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