Mortar Calculator
Estimate whole mortar bags for bricks, blocks or a known application area or volume. Use a named product preset or enter the coverage from your bag; the result keeps your allowance and whole-bag rounding visible.
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How Many Bags of Mortar Do I Need?
Divide the work quantity by the matching coverage on the bag or technical sheet. For masonry, that may be bricks or blocks per bag; for a coating or bed, it may be area at a stated thickness. A known wet-volume estimate needs the bag's mixed volume yield instead.
Bag equivalents = quantity to install ÷ matching coverage per bag
Bags to buy = bag equivalents × (1 + allowance ÷ 100), rounded up
Use this mortar calculator for block or brick work after counting the units that will actually be laid. Spare masonry units kept for breakage do not all need mortar. If you still need that count, use the concrete block calculator or brick calculator; carry over the installation quantity rather than every spare unit purchased.
Example: mortar for 100 standard blocks
Using a selected bag coverage of 12 blocks, 100 ÷ 12 = 8.33 bag equivalents. That rounds to 9 bags with no added allowance. With a chosen 10% allowance, calculate 8.33… × 1.10 = 9.16… and round to 10 bags. Rounding to nine first and then adding the percentage would apply the allowance to an already-inflated quantity.
Mortar Coverage per Bag: Match the Product
Bag weight alone does not define masonry coverage. These are two published product examples, not interchangeable recipes or recommendations to choose a mortar type.
| Product | Standard bricks per bag | Standard 8 in blocks per bag |
|---|---|---|
| QUIKRETE Mortar Mix No. 1102 | Up to 37 | Up to 13 |
| Sakrete Mortar Mix Type S | 35 | 12 |
QUIKRETE's data sheet describes its block example as 8 × 8 × 16 in. Sakrete's technical sheet labels its yield approximate and excludes waste and spillage. Neither figure makes a bag's coverage universal for larger bricks, thicker joints, fully bedded units or irregular stone.
If your product lists a range, enter the rate appropriate to the specified application; using the lower coverage gives the larger bag estimate. Select custom coverage for a different bag size. The tool does not scale an 80 lb example to another package and present that as a manufacturer's published yield.
What if the label gives square feet?
Use area mode with the label's coverage at the thickness or trowel size you will actually use. For example, an area of 120 ft² and a specified coverage of 30 ft² per bag require four bags before allowance. Those figures are an arithmetic example, not a thinset coverage recommendation. Brick-per-bag coverage cannot be substituted for square-foot coverage.
Which Mortar Quantity Are You Estimating?
This is a bagged cement mortar calculator: it estimates a selected product from its published yield. It does not choose Type N or Type S, design a cement-to-sand mix, or turn dry ingredients into wet volume using a generic multiplier.
Mortar in masonry joints is separate from grout filling hollow block cores. Tile-setting mortar also depends on its product and trowel application. Keep those quantities separate instead of adding core volume or a tile-setting rate to a masonry bag estimate.
The optional subtotal is whole bags × the price you enter. It excludes masonry units, delivery, tax, labor and other materials.
Sources & Methodology
Preset rates come from the two named manufacturers. Custom count, area and volume modes divide compatible quantities, apply the entered allowance to unrounded bag equivalents, and round up once. 1 ft² = 0.09290304 m²; 1 ft³ = 0.028316846592 m³. No generic density or mix ratio is used.
- QUIKRETE Mortar Mix No. 1102 technical data sheet — up-to coverage for an 80 lb bag.
- Sakrete Mortar Mix Type S technical data sheet — package-specific masonry yields and waste exclusion.
- TEC product coverage calculator — tile mortar coverage is tied to product and trowel size.
Sources reviewed October 25, 2026.
