01
Formula
Units = wall area × (144 ÷ (nominal length × height)) × (1 + waste).
The result rounds up to a whole unit. Mortar cubic feet = units ÷ 100 × the factor you enter. Change the nominal size if the block is not 16 by 8.
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Concrete block calculator and brick calculator
This concrete block calculator counts standard block from the wall area. Switch the unit to use it as a brick calculator. The mortar line is a planning factor per 100 units, which makes the page a simple mortar calculator as well.
Blocks to order
378blocks
Wall area320 sq ft
Units per square foot1.125
Mortar, planning24.57 cu ft
Planning estimate from the numbers you enter. Coverage, density, waste and price are assumptions, not a supplier quote or an engineering specification.
How it works
Nominal size already includes the joint.
A standard concrete block is counted on a 16 by 8 inch nominal module, joint included. Square inches in a square foot are 144, and 144 ÷ (16 × 8) = 1.125 blocks per square foot. Modular brick is counted on an 8 by 2.666… inch module, which is 6.75 bricks per square foot. Waste covers cuts and breakage. The mortar default is 6.5 cubic feet per 100 block and 8.5 cubic feet per 100 modular brick. Those factors are assumptions for face bedding, not a structural specification. Confirm them with the mortar bag and the bond you are laying.
02
Example
A 40 foot wall, 8 feet high, in 16×8 block.
The area is 320 square feet. At 1.125 blocks per square foot and 5% waste, order 378 blocks. At 6.5 cubic feet of mortar per 100 blocks, the planning mortar is 24.57 cubic feet.
03
Tips
Openings come out of the area.
Doors and windows are not subtracted automatically. Reduce the height or the length, or calculate the opening area and remove those units. Corners, bond beams, and lintels use special units this count does not separate.
04
Equipment
Block and mortar still need a machine on a real wall.
A mixer, a skid steer, or a telehandler moves block and mud. Dengaro arranges financing for business equipment from $15,000 to $2 million. The button opens that application.
Important questions
Know what to expect.
How do I switch this into a brick calculator?+
Choose modular brick. The nominal face becomes 8 by 2.666… inches, which is 6.75 bricks per square foot before waste, and the mortar factor starts at 8.5 cubic feet per 100 bricks.
Is the mortar calculator exact?+
No. Mortar use depends on joint thickness, the bond, and whether you bed the face shells or the full block. The cubic-feet-per-100 field is there so you can use the factor your supplier or bag specifies.
Why 1.125 blocks per square foot?+
Because the nominal 16×8 module, including a 3/8 inch joint, fits 1.125 times into a square foot. Actual block is slightly smaller than nominal. Do not count with the actual face or you will under-order.
Does this include grout or rebar in the cells?+
No. Grout, ladder reinforcement, and vertical bars are a separate takeoff. The rebar calculator is for a flat grid, not for a masonry wall.
Financing built into the sale