RightQty

Hardscape & masonry

Concrete block calculator

Estimate concrete masonry units from net wall face area and add a configurable planning allowance for mortar bags.

Masonry wall

Calculate concrete blocks and mortar

Measurement system
Add all door, window, and other openings together.
Default planning allowance: 35 blocks per bag.
Overage

Covers spillage, uneven depth, settling, and minor measurement differences.

Optional material costAdd your supplier's price

Material only; taxes, delivery, tools, reinforcement, and labor are excluded.

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Your material estimate

Concrete blocks

189blocks

Includes 5% overage and purchase-unit rounding where applicable.

Gross wall area
160 sq ft
Net area after openings
160 sq ft
Approx. mortar bags
6 bags

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Shopping list

  • Concrete masonry unitsNet wall area plus 5% overage.189 blocks
  • Mortar mixPlanning allowance at 35 blocks per bag; verify the product yield.6 bags
Calculation assumptions
  • Nominal block face dimensions include the intended mortar-joint module.
  • The entered opening area is subtracted once from gross wall area.
  • Mortar is estimated at 35 blocks per bag; joint profile, block geometry, and bag yield change actual coverage.
  • Bond beams, lintels, grout, reinforcement, corners, and specialty units are outside this quantity estimate.

Net-area math

How concrete masonry units are estimated

1

Net wall area

Subtract total openings from wall length × wall height.

2

Nominal module

Divide net area by nominal block length × height, including the joint module.

3

Purchase allowance

Add block waste and divide the order count by entered mortar coverage.

Planning boundary

Special units and grout are separate

Corner blocks, bond beams, lintels, cut units, grout, reinforcement, flashing, and control joints depend on the wall design. Mortar coverage varies with joint profile, block geometry, and product yield.