Brick Calculator: How Many Bricks and How Much Mortar?

How to use the brick calculator

1. Choose the project. “Wall” works for garden walls, veneer, planters and columns, measured as length × height. “Fire pit” works out the face area of a round ring from its inside diameter and height.
2. Subtract openings such as doors and windows from a wall.
3. Pick the brick size. Modular (4 × 2⅔ × 8 in nominal) is the most common size in the U.S. If your brick is something else, measure it and choose the closest match.
4. Pick the mortar joint. ⅜ in is standard. A ½ in joint uses more mortar. For modular brick it does not change the brick count.
5. Pick the bond and wythes. Patterns with header courses (common, English, Flemish) use more brick. A single wythe is one brick thick, as in veneer. A solid 8-inch wall is two wythes.
6. Check the waste. The defaults follow the BIA: at least 5% for brick and 15–25% for mortar.

How many bricks per square foot? The formula

The rates come from BIA Technical Note 10, Table 4, for running or stack bond with no waste. Divide by 100 to get bricks per square foot. Modular brick works out to 6.75 per sq ft, and Norman brick to 4.5.

Bond patterns with headers add brick. The BIA correction factors are +⅕ brick and +1/15 mortar for common bond with headers every fifth course, +½ and +⅙ for English bond, and +⅓ and +1/9 for Flemish bond. The BIA’s own example is standard brick in common bond with headers every fifth course. That gives 655 + ⅕ × 655 = 786 bricks per 100 sq ft, and the calculator matches it.

How much mortar for bricks?

The calculator gives the mixed mortar volume and two ways to buy it. Choose one:

• Premixed mortar mix in 80 lb bags. QUIKRETE’s data sheet says one bag lays up to 37 standard bricks. For larger brick we scale that by the extra mortar each brick needs, which is our assumption. “Up to” is the best case, so it is worth buying a bag more than you think.
• Masonry cement and sand. Masons’ rule of thumb is eight bags of masonry cement per 1,000 modular brick. The BIA calls this very rough, with an unspecified amount of waste included. Allow about 1 cu ft of loose, damp sand for each cubic foot of mortar.

Mortar waste is higher than brick waste. Droppings, mortar that stiffens before you use it, and cleanup all add up, so the BIA suggests 15 to 25%. Hollow brick laid on face shells only uses 25 to 35% less mortar. Mortar for the collar joint between two wythes is not included.

Worked examples: a garden wall and a fire pit

A 20 ft × 4 ft garden wall, one wythe of modular brick, ⅜ in joints. 80 sq ft × 6.75 = 540 bricks net, plus 5% = 567 bricks. Mortar is 540 × 8.1 ÷ 1,000 = 4.4 cu ft, or 5.2 cu ft with 20% waste. That is 16 bags of 80 lb mortar mix by the QUIKRETE figure, or 5 bags of masonry cement plus about 5 cu ft of sand.

A brick fire pit 3 ft across inside and 18 in high. With 4 in deep modular brick, the ring’s centerline is 3 ft 4 in across. Its face area is π × 3.33 × 1.5 = 15.7 sq ft, or 106 bricks net and 112 bricks with waste. Mortar is about 1 cu ft, so 4 bags of 80 lb mix. A round ring needs a few more cut bricks than a straight wall. For the inner ring of a wood-burning pit, use firebrick and refractory mortar.

A 100 sq ft wall in Norman brick with ½ in joints. 450 net, plus 5% is 473 bricks. Mortar is 450 × 14.3 ÷ 1,000 = 6.4 cu ft, or 7.7 cu ft with 20%.

Tips for ordering brick

• Buy from one batch. Color varies between production runs, so order everything at once, plus the waste.
• Plan for corners and openings. The BIA notes that partial brick are needed at corners to keep the bond. Walls sized in whole brick lengths cut down on waste.
• Count the footing separately. A brick wall sits on a concrete footing. Use the concrete bag calculator for the footing, and the retaining wall block calculator if the wall will hold back soil.
• Know nominal from actual size. Modular sizes in the table are nominal: the brick plus one mortar joint. The brick itself is made smaller by the joint it is designed for, which is why the count stays the same with either joint. Non-modular sizes such as standard, queen and king are listed by the brick’s real dimensions.
• Brick patios are different. Pavers are laid on sand without mortar joints. Use the paver calculator for those.

Sources & assumptions

How this calculator gets its numbers. Full method: our methodology.

• Bricks = wall area ÷ 100 × brick per 100 sq ft from BIA Technical Note 10, Table 4 (running or stack bond), × (1 + bond correction) × wythes, plus brick waste (BIA: at least 5%).
• Mortar = net bricks × cubic feet per 1,000 brick from Table 4 for the joint chosen, × (1 + bond correction), plus mortar waste (BIA: 15–25%; default 20%). Collar joints between wythes are not included.
• Premixed bags use the QUIKRETE Mortar Mix data sheet figure of up to 37 standard bricks per 80 lb bag. For other brick sizes we scale it by that brick’s mortar demand relative to modular brick at ⅜ in joints (our assumption).
• Masonry cement bags use the BIA rule of thumb of 8 bags per 1,000 modular brick (rough, includes waste), scaled the same way. Sand ≈ 1 cu ft of damp loose sand per cu ft of mortar (BIA).
• Fire pit face area = π × (inside diameter + brick depth) × height, measured on the ring’s centerline.

Sources

1. Brick Industry Association, Technical Note 10: Dimensioning and Estimating Brick Masonry. Table 4 brick and mortar quantities; Table 6 bond correction factors; waste allowances; masonry cement and sand rules of thumb.
2. QUIKRETE, QUIKRETE Mortar Mix (No. 1102) data sheet. Each 80 lb bag lays up to 37 standard bricks or 13 standard 8 × 8 × 16 in blocks; Type N; ASTM C270 and C1714.

Last reviewed October 26, 2026. Product figures vary by brand; the label on what you buy wins.