Formula
The nominal face already includes a 3/8 inch joint:
blocks = wall area × 144 / 128
That is 1.125 blocks per square foot. The nominal unit is 16 inches long and 8 inches high.
Assumptions
- The block is the standard 8-inch-high, 16-inch-long nominal module.
- Joints are included in that nominal face.
- The wall is one thickness.
Worked example
120 square feet of wall is 135 blocks.
Input definitions
- Nominal size
- The module that includes the mortar joint, not the slightly smaller manufactured block.
Limitations
Bond beams, lintels, and a different block size are not counted. This is not a mortar estimate.
Questions
Why 1.125 blocks per square foot?
144 divided by 128 is 1.125. A 10 by 12 foot wall is 120 square feet, which is exactly 135 blocks.
Is this the same as the brick count?
No. Brick uses a modular clay face of 21 square inches. This page uses the 8 by 16 inch concrete module.