Knowing how to calculate CMU block quantity is only the start of a masonry takeoff. A wall is not a pile of blocks. It is units, mortar, grout, reinforcing, ties, flashing, accessories, scaffolding and cleaning, and each one is measured in a different unit and installed at a different pace. This guide walks through a complete masonry takeoff for concrete masonry units (CMU) and brick, with formulas, waste allowances and a worked example you can adapt to your own projects.
If you would rather have the quantities prepared from your drawings, our masonry estimating services deliver units, grout, reinforcing and accessories by wall type. If you want the method first, keep reading.
What a masonry takeoff includes
A complete masonry package usually contains these quantity groups:
- Units: standard CMU, special shapes, brick, stone veneer or glass block, counted by number.
- Mortar and grout: measured by volume or by bag, depending on how your supplier sells it.
- Reinforcing: vertical bars, horizontal joint reinforcement, bond beam steel and lintel bars.
- Accessories: ties and anchors, flashing, weeps, control joint material, cavity drainage and insulation.
- Labor, scaffolding, mortar mixing, protection and cleaning.
For how masonry fits with the structure it sits on, see our overview of concrete and masonry estimating for USA contractors. The footings and slabs below the wall are covered in our guide on how to calculate concrete yardage, rebar and formwork.
Step 1: Gather the right documents
Masonry information is spread across disciplines, so collect all of it before you measure:
- Architectural plans and elevations for wall lengths, heights, openings and veneer areas.
- Wall sections and details for bond beams, lintels, parapets, flashing, control joints and cavity construction.
- Structural drawings and general notes for reinforcing size and spacing, grouting requirements, lap lengths and masonry strength.
- Specifications in Division 04, typically 04 21 13 for brick masonry and 04 22 00 for concrete unit masonry, which set the unit type, mortar type, bond pattern, tolerances and cleaning.
Our guide to reading construction plans for estimating explains how to cross-check these sheets so wall types and heights stay consistent.
Step 2: Calculate CMU quantities
Start with wall area. Multiply the length of each wall type by its height, add parapets and gables, and subtract openings. Measure to the actual top of wall, including stepped footings and sloped tops.
CMU is sized by nominal dimensions that include the mortar joint. A standard 8 x 8 x 16 inch block has a nominal face of 8 by 16 inches, or 128 square inches. One square foot is 144 square inches, so there are 144 / 128 = 1.125 blocks per square foot, or about 113 blocks per 100 square feet. The same ratio applies to 4-, 6-, 10- and 12-inch wide blocks, because only the thickness changes, not the face.
Net block count = net wall area x 1.125. Then count special units on their own lines, because they are priced differently and are installed differently:
- Bond beam blocks at courses that carry horizontal reinforcing and grout.
- Lintel blocks over openings.
- Corner, bullnose, half and jamb units.
- Control joint blocks, sash blocks and pilaster units.
- Cap blocks or solid tops, where specified.
Subtract the special units from the standard count so they are not counted twice. The National Concrete Masonry Association at ncma.org publishes technical resources on unit sizes and wall construction that are useful when a specification is unclear.
Step 3: Calculate brick quantities
Brick works the same way, but sizes vary more. Use the nominal face dimensions, including one mortar joint, to find bricks per square foot: 144 divided by the nominal face area in square inches. A modular brick has a nominal face of about 2-2/3 by 8 inches, or 21.33 square inches, which gives 144 / 21.33 = 6.75 bricks per square foot. Oversize, utility, Roman and norman bricks have different faces and different counts, so always take the actual unit size from the specification or the supplier’s data.
Bond pattern also matters. Running bond is the baseline. Stack bond, Flemish bond, soldier courses, rowlocks, corbels, headers and decorative patterns all need extra cutting and more units. Count special courses, sills, lintel returns and corner details separately and keep them out of the field count. Check the Brick Industry Association at gobrick.com for technical notes on brick sizes, bond and veneer details.
Step 4: Add waste
Add waste for breakage, cutting and handling. Many estimators start with about 5 percent for standard CMU walls and about 5 to 10 percent for brick, with more for complex bond patterns, many corners, narrow piers, arches and curved walls. Treat these as starting points and refine them with your own records of ordered versus installed quantities.
Round up to the way the units are packaged and delivered. Brick is commonly sold by the thousand on pallets or cubes, and CMU is sold by the unit or by the pallet. You cannot order half a pallet, and returns of cut cubes are rarely accepted.
Step 5: Calculate mortar and grout
Mortar quantity depends on unit size, joint thickness, whether face-shell or full bedding is used, and the type of unit. Because those variables interact, most estimators use published tables or the supplier’s figures instead of calculating from scratch. Enter the mortar as cubic feet or as bags of cement and sand by mortar type, matching the type named in the specification. A single mortar line applied across the whole job hides the fact that parapets, exterior walls and below-grade walls often call for different mortar types.
Grout is calculated from the number of grouted cells, not from wall area. Count grouted cells from the structural notes: vertical bars at a given spacing, grouted solid at jambs and corners, and bond beams. Multiply by the cell volume from the unit supplier’s data, then add waste, usually higher than for mortar because of voids, spillage and pump line losses. Note whether grout is placed in low lifts or high lifts, and whether it is pumped, because that changes the price per cubic yard and the labor.
Step 6: Calculate reinforcing and accessories
Vertical reinforcing
Count bars from the spacing. For a wall of a given length at 32 inch spacing, the number of bars is the length in inches divided by 32, rounded up, plus one for the end. Bar length equals wall height plus the lap or embedment into the footing and the bond beam above. Add extra bars at jambs, corners and ends of walls.
Horizontal joint reinforcement
Ladder and truss wire is commonly placed at a vertical spacing set in the specification, such as every second course. Rows = wall height divided by the spacing. Linear feet = rows x wall length, plus an allowance for laps and corner pieces.
Bond beams and lintels
Bond beams need special blocks, continuous horizontal bars and grout. Lintels need lintel blocks or precast or steel lintels at openings, with bars and bearing length on each side of the opening. Take the quantities from the lintel schedule, and watch for steel lintels that belong to another trade. Our guide on how to calculate structural steel tonnage covers how miscellaneous steel is usually split.
Ties, anchors, flashing and weeps
Brick veneer ties are often spaced so that each tie covers no more than a set area, commonly around 2.67 square feet, but codes and specifications vary. Divide veneer area by the area per tie, then add extra ties around openings and at the tops of walls. Flashing is measured in linear feet by type: base flashing, head flashing over openings, and through-wall flashing, with laps and end dams. Weeps are counted by spacing along the flashing line. Control joints are measured in linear feet, with backer rod and sealant. Our guide to building envelope estimating explains who normally owns the transitions at openings, flashing and sealants.
Step 7: Labor, access and protection
Masonry labor is driven by wall height, unit size, number of corners and openings, and access. Price scaffolding or mast climbers, hoisting, mortar mixing, winter protection, rain protection, bracing of freestanding walls, and cleaning. A wall that is 14 feet high costs more per square foot than one that is 8 feet high because of scaffold changes and material handling. For production rates, burdens and crew composition, see our guide to construction labor cost estimating.
A worked example
These numbers are illustrative. A CMU wall is 120 feet long and 12 feet high, 8 inches thick, with four 4 x 4 foot windows and two 3 x 7 foot doors.
- Gross area: 120 x 12 = 1,440 sq ft.
- Openings: 4 x 16 + 2 x 21 = 106 sq ft.
- Net area: 1,334 sq ft.
- Blocks: 1,334 x 1.125 = 1,500.75, so 1,501 units before specials.
- With 5 percent waste: about 1,576 units.
Reinforcing, assuming #5 vertical bars at 32 inches and a 40-bar-diameter lap (about 2.1 feet):
- Bars: 120 x 12 / 32 = 45 spaces, plus one, so 46 bars.
- Bar length: 12 + 2.1 = 14.1 ft, so 46 x 14.1 = about 648 linear feet.
- Weight: 648 x 1.043 lb per foot = about 676 lb.
- Joint reinforcement every second course (16 inches): 12 x 12 / 16 = 9 rows x 120 ft = 1,080 ft, plus 5 percent for laps, so about 1,134 ft.
For a brick veneer wall of 80 feet by 10 feet with 120 square feet of openings:
- Net area: 800 – 120 = 680 sq ft.
- Modular brick: 680 x 6.75 = 4,590 bricks.
- With 8 percent waste: about 4,958 bricks.
- Ties at 2.67 sq ft each: 680 / 2.67 = 255 ties, before extras at openings and wall tops.
Grout, mortar, flashing, weeps, control joints, scaffolding and labor are then added as their own lines.
Items that are commonly missed
- Special block shapes, which are a different price and a different delivery.
- Grout in cells at jambs, corners and below bond beams.
- Dowels and starter bars between the footing and the first course.
- Flashing at heads, sills, bases and parapets, with end dams and laps.
- Cavity insulation and air barrier, which may be in another trade’s scope.
- Control joints and expansion joints, with backer rod and sealant.
- Scaffolding, mast climbers, and weather protection.
- Cleaning, sealers and anti-graffiti coatings where the spec calls for them.
Common masonry takeoff mistakes
- Using one block count for a wall that contains bond beams, lintels and jamb units.
- Forgetting that nominal and actual dimensions are different, and measuring walls by the wrong one.
- Applying brick counts per square foot from a different unit size.
- Ignoring grout volume and pumping, which can exceed the unit cost on heavily grouted walls.
- Pricing walls at one height rate when scaffolding changes at 8, 12 and 16 feet.
- Omitting flashing, weeps and ties, which are small items that are costly to fix later.
- Not stating whether steel lintels and shelf angles are included.
The broader list of estimating mistakes is in our post on common construction estimating mistakes, and our material takeoff guide shows how to structure quantities so nothing falls between trades.
Frequently asked questions
How many 8 x 8 x 16 blocks are in 100 square feet of wall?
About 113, since each block covers 0.889 square feet including the mortar joint. With 5 percent waste, order about 119 blocks per 100 square feet.
How many bricks are in a square foot of wall?
For modular brick with a nominal 2-2/3 x 8 inch face, about 6.75 per square foot. Other brick sizes give different counts, so always check the specified unit.
Do I deduct openings from the masonry area?
Most estimators deduct openings, since units are not placed there, and then add lintels, jamb units and cutting waste around them. Apply the same rule on every job.
What waste factor should I use for masonry units?
Many estimators use about 5 percent for CMU and 5 to 10 percent for brick, with higher figures for complex patterns. Use your own history where you have it.
Is grout measured by wall area?
No. Grout is measured by the number of grouted cells and bond beams, converted to volume using the unit supplier’s data for the block size you are using.
How do I price masonry labor?
By unit count or area, adjusted for wall height, access, corners, openings and bond pattern. Use production rates from your own completed work where possible.
Get a masonry takeoff prepared from your drawings
We extract CMU, brick, grout, reinforcing, ties, flashing and accessories by wall type, so you can apply current supplier pricing and your own labor rates. See our masonry estimation service, our quantity and material takeoffs, or the full list of estimating services by trade. For the unit conversions used in this guide, read our post on takeoff units of measure and conversions.