Concrete Block Calculator

Count the concrete blocks (CMUs) for a wall, with waste.

Wall length

Wall height

Block length

Block height

Waste (%)

Price per block ($)

Blocks needed (blocks) 189

Blocks per ft² (/ft²) 1.125

Total cost ($) 0

Formula: blocks/ft² = 144 ÷ (blockL × blockH)

Step-by-step with your numbers:

1. Values used:

2. Wall length = 20

3. Wall height = 8

4. Block length = 16

5. Block height = 8

6. Waste = 5 %

7. Price per block = 0 $

9. Blocks needed = 189blocks

10. Blocks per ft² = 1.125/ft²

11. Total cost = 0$

Did we solve your problem today?

Estimate the number of concrete blocks (CMUs) for a wall. The standard 16×8 in block (with mortar) covers about 0.89 ft².

The math behind it

Blocks per ft² = 144 ÷ (block length × block height). A 16×8 in block ≈ 1.125 blocks/ft².

Blocks = wall area × blocks per ft², plus waste.

20×8 ft wall (160 ft²) with 16×8 in blocks → 1.125/ft² → 180 blocks (+5% = 189).

How many blocks per square foot?

About 1.125 standard 16×8 in blocks per square foot of wall.