🧱Concrete Block & Cinder Block Calculator
Find how many concrete blocks (cinder blocks) you need, plus mortar and core fill.
Your wall
You'll need about
198 blocks
160 sq ft of wall · 7 bags of mortar (incl. 10% waste)
sq ft
160
blocks
198
mortar bags
7
fill cu yd
0.00
🛒 Shopping list
- Concrete blocks (8 × 8 × 16 in)198 blocks
- Mortar mix (80 lb)7 bags
Concrete blocks and cinder blocks share the same 8 × 16 inch face, so the count works for either.
How it works
Concrete blocks and cinder blocks share the same 8 × 16 in face, so the math is the same: blocks = wall area × 1.125 per sq ft, plus waste. Mortar ≈ one 80 lb bag per 30 blocks. If you fill the cores, an 8 in block takes about 0.0111 cubic yards of grout (about 90 blocks per yard).
Worked example
A wall 40 ft long and 4 ft high = 160 sq ft × 1.125 = 180 blocks, × 1.1 waste = 198 blocks and 7 bags of mortar. Filling every core would take about 2.2 cubic yards.
Questions people ask
Today they're the same size and are counted the same way. True cinder blocks used coal ash; most modern blocks are concrete.
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Last updated October 8, 2026. These results are friendly estimates to help you plan — always double-check before buying or making big decisions.