Brick & Block Calculator
Brick or block quantities from wall dimensions, unit size and mortar joint.
Project inputs
Examples
Supplier prices (optional)
Prices exclude delivery, tax and labor. Currency changes labels only.
Estimate
Start with your measurements.
Your order quantity, purchasing options and material cost appear here.
Overage is included in purchasing quantities. Check product yields before ordering.
Check product yields and project specifications. Material subtotals exclude delivery, tax, labor and equipment. These quantities do not specify structural dimensions or reinforcement.
Estimate
Worked example
A 20 × 4 ft wall has 80 ft² of face area. A modular brick with a ⅜-inch joint covers (7.625 + 0.375) × (2.25 + 0.375) = 21 in². That is 144 ÷ 21 = 6.857 bricks/ft². With 10% overage, round 80 × (144 ÷ 21) × 1.10 up to 604 bricks. If your mortar bag covers 32 bricks, round 604 ÷ 32 up to 19 bags. The 32-brick coverage is an example, not a product specification.
Calculation method
The calculator first computes wall face area (length × height). It then multiplies by the coverage rate for the selected brick or block type; which accounts for the mortar joint size; to get the base unit count. Your waste factor is added and the result is rounded up to a whole number.
Mortar bags use the coverage you enter from the selected product instructions. Joint size, brick shape, wall thickness and technique affect mortar use. Unit counts cover one wall face and do not subtract openings or include extra wythes.
Count formula: wall area × 144 ÷ [(face length + joint) × (face height + joint)], then apply overage and round up. Both 4-inch and 8-inch-wide CMU have the same nominal 8 × 16-inch face. CMHA masonry dimensions; Acme king brick dimensions.
Project notes
- Dry-stack first, then mortar. Lay out a full course of bricks or blocks without mortar to confirm your layout and spacing before committing. This is especially helpful around corners and openings.
- Plan course heights. Check the layout and joint dimensions against your wall design.
- Butter both sides. Apply mortar to the bed (horizontal joint) and the head (vertical joint) of each unit for maximum bonding. Skipping the head joint weakens the wall significantly.
- Keep mortar workable. Mortar that sits more than 60–90 minutes starts to stiffen and loses bonding strength. Mix only what you can use in that time, especially in hot or windy weather.
- Cure slowly. Protect freshly laid brick work from direct sun, rain, and freezing temperatures for at least 48–72 hours. Cover with burlap or plastic sheeting if conditions are extreme.
- Check plumb and level constantly. Use a spirit level after every 2–3 courses. Errors compound quickly; a wall that's 1/4 inch out of plumb at the bottom will be noticeably crooked by the time it's 4 feet tall.
Input and ordering checks
Unit size and joints. Coverage depends on the selected face dimensions and mortar joint. Confirm both against your product.
Not accounting for cuts. Openings (doors, windows) reduce the brick count, but cutting waste around them can easily use up 5–10% of your order. The 10% waste factor helps, but for walls with multiple openings, increase it to 15%.
Underestimating mortar. Many first-timers forget mortar entirely in the cost estimate, or assume one bag goes much further than it does. Mortar can add 10–20% to your total material cost.
Mixing too much mortar at once. If mortar stiffens before you use it, the temptation is to add water and re-temper it. This weakens the mix and is considered bad practice. Mix in small batches and discard anything that's been sitting for over 90 minutes.
Assumptions
- ◦Face coverage: With a ⅜-inch joint: modular brick 6.857/ft²; king brick 4.8/ft²; both CMU widths 1.125/ft². Joint changes recalculate the face coverage.
- ◦Mortar yield: Enter the selected bag’s unit coverage. No universal bag weight or coverage is assumed.
- ◦Single wythe (one unit thick): This calculator assumes a single layer (wythe) of brick or block. For double-wythe or cavity walls, multiply the unit count by the number of wythes.
- ◦No openings deducted: The calculator does not subtract area for doors, windows, or other openings. Deduct opening area from wall area manually before calculating if needed.
- ◦Results are estimates: Actual material quantities vary with mason technique, joint consistency, and site conditions. Verify quantities with your supplier.