Brick Calculator
Calculate how many bricks you need for walls, patios, walkways, and fire pits. Accounts for mortar joints and waste.
How to Calculate Bricks for Your Project
The number of bricks you need depends on the project type, brick size, and whether you are using mortar joints. For walls, calculate the face area (length × height) and multiply by the number of bricks per square foot — typically about 7 for standard bricks with a 3/8-inch mortar joint. For patios and walkways where bricks are laid flat, you need about 4.5 standard bricks per square foot. Fire pits are calculated by the circumference of the circle multiplied by the number of rows. Always add at least 10% extra for cuts, breakage, and waste.
Brick Sizes Comparison
| Brick Type | Dimensions (L × W × H) | Wall (per sq ft) | Patio (per sq ft) |
|---|---|---|---|
| Standard | 8" × 3.625" × 2.25" | ~7 bricks | ~4.5 bricks |
| King Size | 9.625" × 2.75" × 2.75" | ~5.8 bricks | ~4.0 bricks |
| Modular | 7.625" × 3.625" × 2.25" | ~7.5 bricks | ~4.8 bricks |
Mortar vs. Dry-Laid Bricks
Walls always require mortar to bond bricks together for structural integrity. Patios and walkways can be either mortared or dry-laid. Dry-laid patios use sand between the joints and sit on a compacted gravel base — they are easier to install and repair but may shift over time. Mortared patios are more permanent but require a concrete slab underneath. For dry-laid installations, you will not need mortar but should plan for a sand base and polymeric sand for the joints.
Brick Patterns for Patios
- Running Bond: The most common pattern, with each row offset by half a brick. Easy to lay and produces minimal waste.
- Herringbone: Bricks are set at 45-degree or 90-degree angles. Very stable for driveways and high-traffic areas but requires more cutting.
- Basket Weave: Pairs of bricks alternate horizontal and vertical orientation. Creates a classic look with minimal cutting.
- Stack Bond: Bricks are aligned in a grid pattern. Simple and modern looking but less structurally interlocking.
Tips for a Successful Brick Project
- Order all bricks from the same lot to ensure consistent color and sizing.
- For patios, prepare a 4-inch compacted gravel base topped with 1 inch of leveling sand.
- Use a string line and level to keep courses straight and plumb for walls.
- Wet bricks slightly before laying them with mortar — dry bricks absorb moisture from mortar too quickly.
- Consider using pavers instead of bricks for patios if you want a wider range of shapes and colors.
Frequently Asked Questions
A 10x10-foot patio has an area of 100 square feet. Using standard bricks laid flat, you need approximately 4.5 bricks per square foot, which gives you 450 bricks. Adding the recommended 10% waste factor brings the total to about 495 bricks. If you use a herringbone or diagonal pattern, order an additional 5% (around 520 bricks total) to account for extra cutting at the edges.
Not necessarily. Most residential brick patios are dry-laid, meaning the bricks sit on a bed of compacted sand over a gravel base. The joints are filled with polymeric sand, which hardens when wet to lock the bricks in place. Dry-laid patios are easier to install, allow for drainage, and individual bricks can be replaced if damaged. Mortared patios are more permanent but require a concrete slab foundation and are more difficult to repair.
A typical 4-foot diameter fire pit that is 3 rows high requires about 80 to 100 standard bricks. The exact count depends on whether you use mortar joints and the brick size. To calculate it yourself, multiply the circumference (diameter × 3.14) by the number of rows, and divide by the length of one brick (in feet). Add 10% for waste and cutting. Use fire-rated bricks or fire brick for the interior ring.
The most common brick in the U.S. is the standard (modular) brick, measuring 8 inches long, 3.625 inches wide, and 2.25 inches tall. With a standard 3/8-inch mortar joint, the nominal dimensions become 8 × 4 × 2.67 inches, which makes layout math easier. King size bricks are larger at 9.625 × 2.75 × 2.75 inches. Actual dimensions can vary slightly by manufacturer.
For brick walls, plan on one 80-pound bag of mortar mix for every 35 bricks. This accounts for bed joints (horizontal) and head joints (vertical) using a standard 3/8-inch joint thickness. A wall that requires 500 bricks would need approximately 15 bags of mortar mix. Dry-laid patios do not use mortar, but you will need about 1 bag of polymeric sand per 25 to 50 square feet of patio, depending on joint width.