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Concrete Block & Mortar Calculator

Estimate standard concrete blocks, mortar bags, and a cut and breakage allowance for a wall.

Reviewed
2026-09-05
Units
US + metric

Calculated result / live

26 CMU blocks

Order 26 blocks and about 1 bags of mortar for the wall area, then verify the joint and product yield.

10.00 ft × 2.00 ft wall, 16.0 in × 8.0 in face, 8 in nominal depth, and 10% waste.

Input panel

Project measurements

Secondary quantities
Wall area20.0 ft²
Base block count23
Ordered blocks26
Mortar bags1

Calculation trace

Formula with your numbers

20.0 ft² ÷ (16.0 × 8.0 ÷ 144) = 23 blocks; × (1 + 10 ÷ 100) = 26; mortar ÷ 0.5 ft³/bag = 1 bags

26 CMU blocks
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What this concrete block & mortar calculator calculates

A standard 8 × 8 × 16 in block covers 0.889 ft² of nominal wall face. A 16 × 8 ft wall therefore needs 144 blocks before cuts and waste.

Formula

Wall length × wall height ÷ block face area = blocks; mortar volume ÷ product yield = bags.

Worked example

A 16 × 8 ft wall is 128 ft². Dividing by 16 × 8 ÷ 144 gives 144 nominal blocks before the selected waste percentage.

Ordering decision

Openings, bond pattern, lintels, cores, grout, and reinforcement need a wall-specific takeoff.

The page cites the applicable Uzi Tools reference table beside the calculator. Product labels, current editions, local code, and a licensed professional govern structural, electrical, and life-safety work.

02

How to use it

  1. Enter the measured dimensions and keep the displayed units beside each field.
  2. Review the concrete blocks and mortar for a wall result and the substituted formula before ordering.
  3. Adjust waste for the layout, cut pattern, product package, and site conditions.
  4. Copy or print the material list, then verify the cited product data and local requirements.
03

Concrete blocks and mortar for a wall

Use this block calculator for a rectangular wall face. It estimates standard 8 × 8 × 16 in CMU count and mortar bags from wall area, then adds breakage allowance.

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Limits and professional review

Measurements, product yield, waste, moisture, and site conditions can change the order quantity. Local code and a licensed professional govern structural and electrical work.

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Data sources

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Related calculations

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Same-project tools

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Questions specific to this estimate