Block calculator: how many blocks do I need?

Put in your wall length and height, take off any doors or windows, and see how many concrete or aircrete blocks to order.

Wall area
14.4 m²
Blocks to order
152

Based on 10 standard 440 × 215mm blocks per m² with 10mm joints. Wall thickness changes the block, not the count.

How it works

  1. 1Measure the wall length and height in metres.
  2. 2Take off openings. Subtract the area of any doors and windows.
  3. 3Pick the block. Standard UK blocks all have a 440 × 215mm face, so 100mm, 140mm and 215mm blocks all work out at 10 per m². The thickness changes the block, not the count.
  4. 4Add a cuts allowance. 5% is usual, or 10% if there are lots of corners and openings.

Need the mortar too? Use the mortar calculator, or see UK brick and block sizes.

Now find the cheapest place to buy

Take your quantities across to Price Planter and compare them across UK builders' merchants — including whether splitting the order across two merchants works out cheaper.

Compare material prices

Block quantities assume 10mm mortar joints, giving 10 blocks per m². Treat them as a guide and confirm with your bricklayer and merchant before ordering.

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