Cinder Block Calculator
Face-count for a block wall using the 16×8-inch module. Click any i for detail.
Wall
Length (ft)
i
Length
Wall length in feet. |
|
|---|---|
Height (ft)
i
Height
Wall height in feet. |
|
Waste (%)
i
Waste
Cuts, breakage, bond. 5% is a common extra. |
How to use this calculator
- Enter wall length and height.
- This assumes 8×8×16 nominal blocks including mortar joints in the 16×8 face.
- Deduct openings separately, or raise waste.
- Round up.
Results explained
Each block covers 16/12 × 8/12 ≈ 0.89 sq ft of wall face. Count is wall area ÷ that module × (1 + waste%).
Quick reference: block
An 8-inch-high course is 0.667 ft. A 4-ft wall is 6 courses.
| Item | Detail |
|---|---|
| Face module | 16 in × 8 in ≈ 0.89 sq ft |
| Blocks per 100 sq ft | ~113 before waste |
| Half blocks | Count in waste or add openings math |
| Mortar | Not converted to bags on this page |
Bond beam, lintels, and corners need extras your mason will call out.
How the estimate is built
Blocks = (L × H) ÷ (16/12 × 8/12) × (1 + waste%).
Example scenario
20 × 4 ft = 80 sq ft → 80 / 0.889 ≈ 90, plus 5% ≈ 95 blocks.
FAQ
Different block size?
Scale the face module. 12-inch-high blocks cover more per unit.
Foundation wall?
Quantity still works; waterproofing and fill are separate.
Retaining wall cost?
See retaining wall cost for dollars.