Structural Fill Tool

Cinder Block Grout
Calculator

Precision volume estimates for filling hollow masonry cores with grout.

Wall Dimensions (Feet)

Block Specifications

Estimation Results

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Pro Tip

A standard 8x8x16 block actually measures 7 5/8" x 7 5/8" x 15 5/8" to account for 3/8" mortar joints.

Understanding Masonry Grout

In masonry construction, "grout" is a fluid mixture of concrete used to fill the hollow cores of cinder blocks. This is different from the mortar used between the blocks. Grout is poured inside to provide structural strength and to bond rebar to the blocks.

How much grout per block?

A standard 8x8x16 cinder block with two hollow cores requires approximately 0.22 cubic feet of grout to fill completely.

  • Full Grout: Filling every core in the wall.
  • Partial Grout: Filling only the cores that contain vertical rebar (usually every 32-48 inches).