How many bags of mortar do I need for 100 bricks?

At roughly 30 to 40 bricks per 60-pound bag of premixed mortar, 100 bricks needs 3 to 4 bags. Always add 10 to 15 percent overage — buy 4 bags for a 100-brick project to account for waste, mixing, and mortar dropped during installation.

What is the difference between mortar and thinset?

Traditional masonry mortar (used for laying brick, block, or stone) contains Portland cement, lime, and sand. Thinset mortar (used for tile) is a Portland cement-based adhesive without lime, often containing polymer additives for adhesion. Do not use masonry mortar to set tile or thinset to lay brick — they are different products for different applications.

How do I know what notch trowel size to use for thinset?

Trowel notch size is determined by tile size. For tile under 4x4 inches, use a 3/16-inch V-notch. For 4x4 to 12x12, use a 1/4x1/4-inch square notch. For 12x12 to 18x18, use a 1/4x3/8-inch notch. For tile larger than 18x18, use a 1/2x1/2 inch or larger. When in doubt, use the next size up — insufficient mortar coverage causes tiles to crack or hollow out over time.

How long does unmixed mortar last in the bag?

Dry premixed mortar and Portland cement have a shelf life of about 6 to 12 months in an unopened bag stored off the ground in a dry location. Once a bag is opened, moisture from the air begins to degrade the cement content — use opened bags within a few weeks. Never use mortar that has clumped or hardened in the bag, as the cement has already partially hydrated and will not develop full strength.

How Much Mortar Do I Need? Brick, Block & Tile Guide

One 60-pound bag of premixed mortar covers roughly 30 to 40 bricks for standard brick laying, or about 8 to 10 concrete blocks. For tile thinset, one 50-pound bag covers 40 to 60 square feet at standard thickness. Here is how to calculate mortar for any masonry project.

Mortar for Brick Walls

Brick mortar coverage depends on brick size, joint thickness, and mortar type (pre-mixed vs. site-batched). For standard modular brick (7-5/8 x 3-5/8 x 2-1/4 inches) with a 3/8-inch mortar joint, the rule of thumb is approximately 7 cubic feet of mortar per 1,000 bricks, which works out to one 60-pound bag of premixed mortar per 30 to 40 bricks. A 100-square-foot brick wall in standard running bond pattern contains roughly 700 bricks (7 bricks per square foot), so it needs about 18 to 20 bags of premixed mortar.

For larger blocks — traditional 8x8x16 concrete masonry units (CMU) — mortar consumption per unit goes up because the joints are longer and the beds are thicker. A 60-pound bag of mortar covers roughly 8 to 10 standard CMU blocks. A 100 sq ft concrete block wall at one block thick (about 113 blocks) needs 12 to 14 bags. Factor in a 10 to 15 percent overage for waste, mixing errors, and the mortar that ends up on the ground during learning curve.

Always check the coverage printed on the mortar bag for the brand you are buying — coverage varies between manufacturers and formulations. The mortar calculator on ProBuildCalc lets you input wall area, unit type, and joint size to get a bag count matched to your specific project.

Mortar Mix Ratios: What They Mean

Mortar is a mixture of Portland cement, hydrated lime, and mason's sand in ratios that vary by application. Type S mortar (1 part Portland cement, 1/2 part lime, 4.5 parts sand) is the most common specification for below-grade, load-bearing, or high-strength masonry work. Type N mortar (1 part cement, 1 part lime, 6 parts sand) is a softer mix used for above-grade, non-load-bearing applications and is the most common general-purpose masonry mortar. Type M is high-strength for foundations and below-grade; Type O is low-strength for non-load-bearing interior work.

For most homeowner projects — brick veneer, garden walls, chimney repointing — Type N is the right specification and the most available premixed product at home centers. If you are batching on-site, buy Portland cement, Type S hydrated lime, and coarse mason's sand separately. A standard Type N batch is approximately 1 bag Portland cement (94 lbs), 1 bag lime (50 lbs), and 4 to 5 cubic feet of sand, which makes about 4.5 cubic feet of finished mortar and covers roughly 700 to 800 bricks.

Free tool: Mortar Calculator →

Thinset Mortar for Tile

Thinset mortar (also called tile adhesive or tile mortar) is a different product from masonry mortar. It is a Portland cement-based adhesive used to bond ceramic, porcelain, and stone tile to floors and walls. Coverage depends heavily on trowel notch size, which is chosen based on tile size. A 3/16-inch V-notch trowel for small tile (under 4x4) covers about 55 to 65 square feet per 50-pound bag. A 1/4x1/4-inch square notch for medium tile (4x4 to 12x12) covers 40 to 55 square feet. A 1/2x1/2-inch square notch for large-format tile (12x12 and bigger) covers 30 to 40 square feet.

The reason large tile needs a bigger notch is back-buttering and ensuring full coverage — with large tile you need more mortar mass to fill any unevenness in the substrate. For large-format porcelain (24x24 and above), a 3/4-inch notch trowel drops coverage to about 20 to 30 square feet per bag, meaning a 200 sq ft floor installation can require 7 to 10 bags of thinset. Always add 10 to 15 percent to your calculated thinset quantity for waste, cleanup, and the mortar left in the bucket.

Estimating and Buying the Right Amount

The biggest mistake homeowners make with mortar is underbuying and then discovering the product is out of stock or from a different lot when they return to the store. Mortar is not a critical dye-lot match item the way tile is, but consistency in batch batching matters for color consistency in grout joints, particularly with gray or tan tinted mortars. Buy all the mortar you need upfront, then return unopened bags if you have significant overage.

To estimate mortar for a project: determine the total area or unit count, find the per-unit or per-square-foot coverage for the mortar type you are using (from the bag or manufacturer's spec sheet), divide total by coverage, and add 10 to 15 percent for waste and error. Use the ProBuildCalc mortar calculator to do this math instantly — choose your masonry unit type or tile size, enter the area, and get a bag count and approximate cost range.

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FAQ

How many bags of mortar do I need for 100 bricks?: At roughly 30 to 40 bricks per 60-pound bag of premixed mortar, 100 bricks needs 3 to 4 bags. Always add 10 to 15 percent overage — buy 4 bags for a 100-brick project to account for waste, mixing, and mortar dropped during installation.
What is the difference between mortar and thinset?: Traditional masonry mortar (used for laying brick, block, or stone) contains Portland cement, lime, and sand. Thinset mortar (used for tile) is a Portland cement-based adhesive without lime, often containing polymer additives for adhesion. Do not use masonry mortar to set tile or thinset to lay brick — they are different products for different applications.
How do I know what notch trowel size to use for thinset?: Trowel notch size is determined by tile size. For tile under 4x4 inches, use a 3/16-inch V-notch. For 4x4 to 12x12, use a 1/4x1/4-inch square notch. For 12x12 to 18x18, use a 1/4x3/8-inch notch. For tile larger than 18x18, use a 1/2x1/2 inch or larger. When in doubt, use the next size up — insufficient mortar coverage causes tiles to crack or hollow out over time.
How long does unmixed mortar last in the bag?: Dry premixed mortar and Portland cement have a shelf life of about 6 to 12 months in an unopened bag stored off the ground in a dry location. Once a bag is opened, moisture from the air begins to degrade the cement content — use opened bags within a few weeks. Never use mortar that has clumped or hardened in the bag, as the cement has already partially hydrated and will not develop full strength.