Brick Calculator
Estimate for running or stack bond. Check the size with your brick supplier and the tie spacing with your building department.
A wall of modular brick takes 6.75 bricks per square foot. A 20 × 8 ft veneer wall with a 20 ft² door has 140 ft² of brick, so 945 bricks, or 993 with 5% waste. It needs about 28 bags of 80 lb mortar mix and 53 wall ties. Enter your wall and brick size below.
How many bricks per square foot?
| Brick | Actual size (in.) | Per ft² | Per 100 ft² | Per 80 lb bag |
|---|---|---|---|---|
| Modular | 3⅝ × 2¼ × 7⅝ | 6.75 | 675 | 38 |
| Engineer modular | 3⅝ × 2¹³⁄₁₆ × 7⅝ | 5.63 | 563 | 36 |
| Closure modular | 3⅝ × 3⅝ × 7⅝ | 4.50 | 450 | 34 |
| Roman | 3⅝ × 1⅝ × 11⅝ | 6.00 | 600 | 29 |
| Norman | 3⅝ × 2¼ × 11⅝ | 4.50 | 450 | 27 |
| Engineer Norman | 3⅝ × 2¹³⁄₁₆ × 11⅝ | 3.75 | 375 | 26 |
| Utility | 3⅝ × 3⅝ × 11⅝ | 3.00 | 300 | 25 |
| Queen | 2¾ × 2¾ × 8 | 5.50 | 550 | 47 |
| King | 3 × 2¾ × 9¾ | 4.55 | 455 | 37 |
| Standard | 3⅝ × 2¼ × 8 | 6.55 | 655 | 37 |
How to calculate how many bricks you need
Brick is estimated by wall area. That is the method the Brick Industry Association (BIA) gives in Technical Note 10:
- Wall area: length × height, minus doors and windows.
- Bricks: wall area × bricks per square foot for your size.
- Waste: add at least 5% for breakage and cuts. TN 10 calls 5% a general minimum, so go higher for many corners and openings.
A 20 × 8 ft wall is 160 ft². Take off a 3 × 6⅔ ft door (20 ft²) and 140 ft² remain. Modular brick runs 6.75 per square foot, so 140 × 6.75 = 945 bricks, and 945 × 1.05 = 993 to order.
Why modular brick is 6.75 per square foot
A modular brick is 7⅝ in. long and 2¼ in. high. With a ⅜ in. joint it fills a nominal 8 × 2⅔ in. space: three courses make 8 in. That space is 21⅓ in², and 144 ÷ 21⅓ = 6.75. Every size in the table above works the same way. Modular brick keeps its count with a ½ in. joint because the brick itself is made smaller. A non-modular brick such as the standard 3⅝ × 2¼ × 8 in. drops from 6.55 to 6.16 per ft² when the joint grows from ⅜ to ½ in.
How much mortar for brick?
The calculator works out the volume of the head and bed joints for your brick and joint. That figure is shown as mortar in the joints and matches the BIA table for modular brick: about 5.5 ft³ per 100 ft² of wall.
Bagged mortar goes further on paper than on the wall, because some is dropped, scraped off, and left in the board. So bags are counted from QUIKRETE's own figure: an 80 lb bag of Mortar Mix lays up to 37 standard bricks. Each size is scaled by its joint volume. That works out to about 38 modular, 27 Norman, or 25 utility brick per bag. The 140 ft² example needs 28 bags with a 10% reserve.
- Per 1,000 modular bricks: about 26 bags of 80 lb mortar mix before waste, 29 with 10%.
- Mixing your own: BIA notes the rule of thumb that 8 bags of masonry cement lay about 1,000 modular brick, and that a cubic foot of damp sand yields about a cubic foot of mortar.
- Waste: TN 10 suggests adding 15 to 25% to theoretical mortar. Because the bag count already starts from a field figure, 10% is the default here.
Brick veneer: ties and air space
Most new brick in the US is a single wythe of veneer tied to a framed or block wall behind it. The IRC (R703.8.4.1) lets each tie support no more than 2.67 ft² of wall, spaced at most 32 in. on center horizontally and 24 in. vertically. With studs at 16 in. on center, a tie every 24 in. up each stud hits that limit exactly. The calculator divides the brick area by 2.67, so the 140 ft² wall needs 53 ties.
Openings need extra ties around their edges, and local rules on spacing there differ. Ask your building department, and check the wind-pressure limits for your area, before you order.
Garden walls, double-wythe walls, and steps
- Single wythe: a freestanding 4 in. wall, a planter, or a barbecue surround. Same count as veneer, without ties. A tall freestanding wall needs reinforcement and engineering, not just brick.
- Double wythe: two layers of brick side by side, about 8 in. thick. The count doubles. If the joint between the layers (the collar joint) is filled solid, the calculator adds BIA's collar-joint mortar: 3.13 ft³ per 100 ft² at ⅜ in.
- Bond patterns: the counts assume running or stack bond. Patterns with headers, such as common or Flemish bond, use more brick. TN 10 adds a fifth more for common bond with a full header course every fifth course.
- Footings: brick walls sit on a concrete footing. Size it with the footing calculator. For a block backup wall, use the concrete block calculator.
About these figures: brick counts follow BIA Technical Note 10, Table 4, and are calculated, not tested. Mortar bags are scaled from QUIKRETE's published 37 standard bricks per 80 lb bag. Tie spacing is the IRC prescriptive limit as quoted by county building departments. Your supplier's brick size, the bag label, and your local code take priority.
Frequently asked questions
How many bricks are in a square foot?
About 6.75 for modular brick with a ⅜ in. joint. Standard brick runs 6.55, queen 5.5, king 4.55, Norman 4.5, and utility 3. These are the BIA Technical Note 10 figures, before waste.
How many bricks do I need for a 10 × 8 wall?
About 567 modular bricks. The wall is 80 ft², 80 × 6.75 = 540 bricks, and 5% waste brings it to 567. Take doors and windows off the area first. Mortar for that wall is about 16 bags of 80 lb mix with a 10% reserve.
How many bricks are in 100 square feet?
675 modular bricks, or 709 with 5% waste. A double-wythe wall, two bricks thick, takes twice as many: 1,350 before waste.
How many bags of mortar do I need for 1,000 bricks?
About 26 bags of 80 lb mortar mix for 1,000 modular bricks, or 29 with a 10% reserve. QUIKRETE says one 80 lb bag lays up to 37 standard bricks. If you mix your own, BIA quotes the rule of thumb of 8 bags of masonry cement per 1,000 modular brick.
How many bricks does a bag of mortar lay?
Up to 37 standard bricks per 80 lb bag of QUIKRETE Mortar Mix. Scaled by joint volume, that is about 38 modular, 27 Norman, or 25 utility bricks. A ½ in. joint lowers each figure by a fifth to a quarter.
How much extra brick should I order?
At least 5%. BIA Technical Note 10 gives 5% as a general minimum for breakage and waste. Use more for walls with many corners, openings, or cut courses, and keep a few spare bricks from the same lot for repairs.
How many brick ties do I need?
One per 2.67 ft² of veneer under IRC R703.8.4.1, so 53 ties for 140 ft². Spacing is at most 32 in. horizontally and 24 in. vertically, with extra ties around openings. Check your local code and wind zone.
What is the difference between modular and standard brick?
A modular brick (3⅝ × 2¼ × 7⅝ in.) plus a ⅜ in. joint is exactly 8 in. long, so it lines up with 8 in. block and 4 in. dimensions. A standard brick is a full 8 in. long, so with the joint it runs 8⅜ in. Counts are close: 6.75 versus 6.55 per square foot.
Related calculators
Sources
- Technical Note 10: Dimensioning and Estimating Brick MasonryBrick Industry AssociationBricks per 100 ft² by size (Table 4), collar-joint mortar (Table 5), bond correction factors, and the 5% brick and 15–25% mortar waste allowances.
- QUIKRETE Mortar Mix (No. 1102) data sheetQUIKRETEEach 80 lb bag lays up to 37 standard bricks or 13 standard 8 × 8 × 16 in. blocks; Type N mortar to ASTM C270.
- Brick veneer handoutKnox County Codes AdministrationIRC R703.8.4.1: each tie supports no more than 2.67 ft² of wall, spaced at most 32 in. horizontally and 24 in. vertically.