Brick & Block Calculator
Bricks or concrete blocks and mortar bagsRuns in your browser
Single-wythe wall (one brick or block thick). For a double brick wall, double the bricks and mortar. Mortar assumes about 40 bricks per 80 lb bag of mortar mix.
Rough material cost
$575Default prices are rough 2026 US big-box averages before tax and delivery. Edit them to match quotes from your local supplier.
Material estimates only. Round up, buy a little extra, and check with your supplier. Structural work (footings, framing, roofs) must follow local building codes; consult a licensed contractor where required.
How it works
Formulas
Units per sq ft = 144 ÷ ((unit length + joint) × (unit height + joint))Actual (not nominal) sizes in inches.
Units = (wall area − openings) × units per sq ft × (1 + waste %)Mortar bags = units ÷ units per 80 lb bag40 modular bricks or 13 8 × 8 × 16 blocks per bag (Quikrete); other bricks scaled by joint volume.
Worked example
Input: A 20 × 4 ft garden wall in modular brick, 3/8 in joints, 5% extra.
- Area: 20 × 4 = 80 sq ft.
- Per sq ft: 144 ÷ (8 × 2.625) = 6.857 bricks.
- 80 × 6.857 × 1.05 = 576 bricks.
- 576 ÷ 40 = 14.4 → 15 bags of mortar.
Result: 576 bricks and 15 bags of mortar mix.
Limits
- Does not include footings, wall ties, rebar, grout fill or sand for site-mixed mortar.
- Retaining and load-bearing walls need engineering and must follow local code.
Sources
- Brick Industry Association, Technical Note 10: Estimating brick masonry
- Quikrete Mortar Mix product data (bricks and blocks per bag)
How to use
- 1Choose the brick or block size.
- 2Enter the wall length and height, and the area of any doors or windows.
- 3Keep the 3/8 in mortar joint unless your plans say otherwise.
- 4Add 5% for breakage and cuts, then read bricks or blocks and mortar bags.
FAQ
How many bricks per square foot?
About 6.86 modular bricks (7⅝ × 2¼ in) per square foot of wall with 3/8 in mortar joints: each brick plus its joint covers 8 × 2⅝ in.
How many concrete blocks per square foot?
1.125 standard 8 × 8 × 16 in blocks. With 3/8 in joints each block covers 16 × 8 in, which is 8/9 of a square foot.
How many bricks can one bag of mortar lay?
Quikrete puts an 80 lb bag of mortar mix at about 40 standard bricks or 13 8 × 8 × 16 blocks. Larger bricks use more mortar each, so fewer per bag.
Is this for a single or double brick wall?
Single wythe (one brick thick). For a double wall, double the bricks and mortar.
Can I use metric units?
Yes. Switch to Metric and enter meters and centimeters; results show cubic meters, square meters or tonnes alongside US units.