◧MeasureThenConstruction Calculators

Cinder Block Calculator

Estimate cinder blocks for walls and foundations.

How It Works

Blocks = ceil(Wall area × 1.125) using the standard 16 × 8 in face.

Example

A 20 ft × 8 ft foundation wall needs 180 cinder blocks.

Frequently Asked Questions

Cinder or concrete block — what is the difference?

Cinder blocks are the lighter, older style; concrete blocks are denser and stronger. Both share the same nominal size.

How are blocks laid?

With mortar in a running bond, usually with cells aligned for optional reinforcing.

Do I need reinforcing?

Rebar and grout-filled cells are code-required for retaining and load-bearing walls in most areas.

More Masonry Calculators

Brick CalculatorEstimate the number of bricks needed for a wall.Concrete Block CalculatorCalculate the number of concrete blocks needed.Mortar CalculatorEstimate the amount of mortar needed for a masonry wall.Masonry Cost CalculatorEstimate the cost of a masonry project.