Concrete Block Quantity Calculator

Find how many concrete blocks per square foot of wall you need with this block calculator. Use the free Concrete Block Quantity Calculator below — enter your values and get instant results, right in your browser. Blocks = wall area (sq ft) × 1.125 (16×8×8 in) or × 1.5 (12×8×8 in), × 1.05 for 5% wastage.

How to use the Concrete Block Quantity Calculator

Concrete blocks build walls far faster than bricks, but their larger face size makes mental estimation harder — a 16×8 inch block covers nearly a full square foot on its own. This calculator tells you how many concrete blocks per square foot of wall you need: 1.125 for the standard 16×8×8 inch block and 1.5 for the smaller 12×8×8 inch size, both including mortar joints. Enter the wall area, add the 5% breakage allowance, and order the exact trolley-loads.

  1. Measure the wall area in square feet and enter it in the Wall area field.
  2. Select your block size from the dropdown.
  3. Click Calculate to see the block count.
  4. Order the With 5% wastage figure to cover broken blocks and cutting.

Formula

Blocks = wall area (sq ft) × 1.125 (16×8×8 in) or × 1.5 (12×8×8 in), × 1.05 for 5% wastage.

Worked example

A 200 sq ft wall with standard 16×8×8 inch blocks: 200 × 1.125 = 225 blocks. With 5% wastage that is 237 blocks — order 240, since dealers sell in round lots. Stack the blocks on level ground under a tarp, because hollow blocks crack if they are dumped carelessly from the trolley.

Frequently asked questions

About 1.125 standard 16×8×8 inch blocks, or 1.5 of the smaller 12×8×8 inch blocks, per square foot of wall.

Yes — the face size is the same, so the count per square foot is identical; only the weight and strength differ.

The 5% wastage covers normal cutting around openings and corners. Deduct large openings from the wall area first.

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