Mortar Calculator

Calculates masonry mortar bag counts and masonry sand tons based on masonry unit count (CMU block, standard modular brick, stone veneer), mortar joint thickness (3/8", 1/2"), and mortar type specifications.

Formula

Mortar Bags = Ceil((Units ÷ Yield per Bag) × (1 + Waste %))

1. Yield per 80 lb Bag: Brick = 140 bricks; CMU Block = 33 blocks; Stone = 30 sq ft 2. Base Bags = Units ÷ Yield per Bag 3. Total Bags with Waste = Ceil(Base Bags × (1 + Waste %))

Inputs

  • Masonry Unit Type
  • Number of Bricks / Blocks / Stone Sq Ft
  • Mortar Type ASTM C270

Worked example

Laying 1,000 standard bricks with 3/8" bed and head mortar joints.

Outcome: 1,000 bricks divided by 140 bricks per 80 lb bag = 7.14 base bags. Adding 15% tooling and board waste gives 8.21 bags, rounding up to 9 full 80-lb bags of Type N mortar.

What is the difference between Type N and Type S mortar?

Type N is a medium-strength mortar (750 PSI) best suited for exterior above-grade walls, chimneys, and residential brick veneer. Type S is high-strength (1,800 PSI) designed for below-grade foundations, retaining walls, and load-bearing block.

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