Concrete block calculator

Concrete Block Calculator

Estimate standard concrete blocks for simple wall areas.

Results

Wall square footage: 80.00 sq ft
Base blocks needed: 90 blocks
Blocks including waste: 99 blocks

Save this calculation to a project estimate.

What this calculator does

This calculator estimates concrete block quantity from wall length, wall height, number of walls, and a selected waste allowance.

It is intended for early material planning on simple wall layouts. It does not account for reinforcing, grout, mortar, bond beams, lintels, or structural requirements.

Block coverage assumption

It uses the standard nominal 8x8x16 inch block face coverage assumption of about 0.8889 square feet per block.

Formula used

Wall square footage equals wall length times wall height times number of walls. The calculator divides that area by the block face coverage and rounds up. Waste is applied to wall area before the final waste-adjusted block count is rounded up.

Estimating reminder

Openings, bond pattern, cuts, broken blocks, and site conditions can change actual block needs, so verify the final order quantity before purchasing.

Frequently asked questions

Does this subtract doors or windows?: No. It estimates from the full wall area entered. If openings are important for your estimate, adjust the wall area before relying on the final order quantity.
Why does the calculator round block counts up?: Blocks are purchased as whole units, so both base and waste-adjusted results are rounded upward.
Does this include mortar or grout?: No. This calculator estimates block count only. Mortar, grout, reinforcement, and labor should be estimated separately.