Free concrete calculator
CMU Block Wall Calculator
Estimate the number of concrete blocks and core fill grout needed for a CMU block wall.
- Estimated block cost ($3.50/ea)
- $1,183
- Grout material cost
- $475
- Total material estimate
- $1,658
- Wall face area
- 300 sq ft
- Ready-mix short-load fee
- None
Estimating Notes
- Standard 8×8×16 blocks have a face area of about 0.89 sq ft, so you need roughly 1.125 blocks per square foot of wall.
- A 50 ft long, 6 ft high wall is 300 sq ft — about 338 standard blocks before breakage waste.
- Add 5% for breakage and cuts, especially on walls with corners, openings, or end blocks.
- Core-fill grout for a fully filled 8-inch wall runs about 0.9 cu ft per block cell — most walls only fill cells with rebar.
- Budget mortar at roughly 3 bags of Type S per 100 blocks laid.
- Factor in mortar, rebar, and core-fill grout separately from the block count — they are often half the material bill.
Calculator FAQs
How many blocks do I need for a wall?
Multiply the wall square footage (length × height) by 1.125 to get the number of standard 8×8×16 blocks. For a 50 ft × 6 ft wall that is 300 × 1.125 ≈ 338 blocks. Add about 5% for breakage and cuts.
How many cinder blocks per square foot?
About 1.125 standard 8×8×16 blocks per square foot of wall face. Each block covers roughly 0.89 sq ft including the mortar joint, so a quick estimate is square footage × 1.125.
How much mortar do I need for a block wall?
Plan on roughly 3 bags of Type S mortar for every 100 blocks laid. A 338-block wall needs about 10 bags. Cold or windy conditions and wider joints raise consumption.
How much does a cinder block wall cost?
Material runs about $2–$4 per block installed for standard gray CMU, so a 338-block wall is roughly $700–$1,350 in block, mortar, and grout before labor. Installed with a mason, expect $10–$20 per square foot depending on height, rebar, and finish.
How much core-fill grout for a block wall?
A fully grouted 8-inch wall uses about 0.9 cu ft of grout per block, but most residential walls only fill the cells that hold rebar — typically every 32–48 inches plus corners. The calculator estimates grout for the cells you choose to fill.