Brick Calculator
Planning a brick wall shouldn’t feel like guesswork. With a reliable brick calculator you can work out how many bricks to order, how much mortar you’ll mix, and what the project will cost—before a single pallet shows up on site. This guide explains the math behind the tool, shows you how to use it step by step, and answers the practical questions builders ask most.
How the Brick Calculator Works
A brick wall is basically area and thickness. The calculator takes your wall dimensions and brick dimensions, then compares the wall’s area to the “coverage area” of one brick including mortar joints. For mortar, it treats the wall as solid volume and subtracts the volume occupied by all the bricks—what’s left is the wet mortar volume. From there you can account for dry bulking and jobsite wastage.
- Wall type: choose a single wythe or a double wythe wall. Double counts two parallel brick layers (the cavity is not included).
- Inputs: enter wall length and height or a total area. You can work in ft, in, m, cm, or mixed ft/in for convenience.
- Brick details: supply the brick’s exposed length (ℓ) and height (h), the wall width (w), and the typical mortar joint (t).
- Outputs: required bricks (rounded up to whole pieces), wet and dry mortar volumes, and optional cost totals when you add prices.
Quick Start: 3-Step Workflow
- Describe the wall. Pick single or double. Enter length and height. If you already know the exact area, fill that instead and it overrides L×H.
- Confirm brick details. For US modular brick, the defaults (8 in × 4 in face with a ⅜ in joint and 4 in width) are a practical starting point. Edit as needed.
- Read the results. You’ll see bricks required and an editable wastage percent (default 5%). Turn on the mortar section to view wet volume, the dry:wet factor, a mix ratio (1:6, 1:5, 1:4, or 1:3), plus cement and sand quantities.
Common Brick Sizes and Joints
Brick dimensions vary by region and manufacturer. In the United States, the Brick Industry Association describes modular brick with a specified size of about 7⅝ in × 2¼ in × 3⅝ in. When you allow a typical ⅜ in mortar joint, the nominal course module becomes roughly 8 in × 2⅔ in × 4 in. That’s why many calculators use 8 × 4 on the exposed face with a ⅜ in joint for planning. See BIA Technical Notes for the full discussion of specified versus nominal dimensions (BIA Technical Notes).
| Item | Typical US value | Notes |
|---|---|---|
| Brick face length (ℓ) | 8 in (nominal) | ≈ 7⅝ in specified + ⅜ in joint |
| Brick face height (h) | 4 in (nominal) | Varies with pattern and manufacturer |
| Wall thickness / brick width (w) | 4 in | Single-wythe thickness. Double wall counts two wythes. |
| Mortar joint (t) | ⅜ in | Common US planning joint; verify project specs |
If you’re using non-modular brick or metric products, just enter the exact dimensions printed on the manufacturer’s data sheet. The calculator works with any consistent units.
Formulas Used (with examples)
1) Wall area
If you’ve entered length and height, the wall area is simply:
Area (A) = Length × Height
If you typed a total area directly, the calculator uses that instead.
2) Bricks per area (including joints)
Every brick occupies a rectangular footprint on the wall when you include joint thickness. Convert everything to a common unit first (the calculator does this for you).
Coverage per brick = (ℓ + t) × (h + t) Bricks needed (exact) = (A × number of wythes) ÷ Coverage per brick Bricks to order = ceil(Bricks needed × (1 + wastage%/100))
Example. A 20 ft × 10 ft single wall has an area of 200 ft². Assuming ℓ = 8 in, h = 4 in, t = ⅜ in (all converted to feet), you’ll get the exact count. Add 5% wastage to allow cutting losses and breakage. Round up to whole bricks.
3) Mortar volumes
Mortar fills the voids between bricks. For a solid single-wythe wall you can model mortar volume as the difference between the wall’s solid volume and the sum of all bricks’ volumes:
Wall volume = (A × w × number of wythes) Brick volume (each) = ℓ × h × w Wet mortar volume = Wall volume − (Bricks needed exact × Brick volume)
To plan material purchases you’ll convert wet volume to a dry volume using a bulking factor. Field practice often uses a factor between 1.3 and 1.6 because sand and cement occupy more space in dry form than the final wet mortar. Our calculator sets 1.52 by default, which you can edit to match your local method or supplier guidance. See discussions in masonry specifications and textbooks, or consult your supplier for a project-specific factor.
Dry volume = Wet volume × (Dry:Wet factor) Total dry volume (with wastage) = Dry volume × (1 + mortar wastage%/100)
4) Material split from mix ratio
Select a volumetric mortar ratio and the calculator divides the total dry volume into cement and sand volumes. A 1:6 mix means 1 part cement to 6 parts sand by volume:
Parts total = 1 + n Cement volume = Total dry volume × (1 / Parts total) Sand volume = Total dry volume × (n / Parts total)
If you enter a cement density (for US jobs a common planning value is ~90 lb/ft³ which is close to 1440 kg/m³) the tool converts cement volume to weight and then to bags. ASTM C270 (ASTM C270) governs mortar materials and properties; suppliers publish densities for their products.
Worked example (US modular)
Let’s run a simple single-wythe wall:
- Wall: 20 ft × 10 ft → A = 200 ft²
- Brick face: ℓ = 8 in, h = 4 in, joint t = ⅜ in
- Width w = 4 in, wastage = 5%
- Dry:Wet factor = 1.52, mortar wastage = 10%
- Mix 1:6, cement density 90 lb/ft³, bag size 110 lb
The calculator returns the rounded brick count, wet and dry volumes, bag count, and sand volume. If you switch to a double wall the area multiplies by two because you’re laying two wythes.
Mortar volumes and mix ratios
Mortar selection depends on exposure, structural demand, and project specs. In North America, ASTM C270 covers mortar types (M, S, N, O) primarily by proportion or property. The volumetric “1:6”-style ratios you see in planning tools are a convenient way to budget cement and sand for general work and repairs. Always follow the project specification for type and proportions.
| Volumetric mix (cement : sand) | Typical use | Notes |
|---|---|---|
| 1 : 6 | Interior plaster, light brickwork | Workable, lower cement content |
| 1 : 5 | General brickwork | Balanced strength and workability |
| 1 : 4 | Exterior plaster, higher demand | Richer mix; faster set, higher strength |
| 1 : 3 | Rich mortar applications | High cement content; use where specified |
The calculator splits your total dry volume into cement and sand per the ratio you choose. If you prefer to drive the calculation by mortar type (N, S, etc.), match the volumetric ratio in your specification or supplier sheet and use that here.
Adding Material Costs
Costing takes only a minute. Enter your price per brick, price per cement bag, and sand price per volume unit (ft³, yd³, m³, or L). The calculator multiplies planned quantities by your prices and displays:
- Cost of bricks (rounded order count × price per brick)
- Cement cost (bag count × bag price)
- Sand cost (sand volume × price per chosen unit)
- Total mortar cost and total wall cost
Pick a currency symbol from the dropdown so your summary reads exactly how you’ll quote it.
Tips for Accuracy
- Measure the opening. Subtract doors and windows from the wall area if you won’t brick over them.
- Confirm the joint thickness. Joint t has a big effect on brick count. Most US jobs use ⅜ in, yet some modular systems use 10 mm or thinner joints.
- Use specified or nominal dimensions consistently. If you enter a specified brick size (without joint), make sure you include the joint thickness as t. If you enter a nominal face size that already accounts for the joint, set t to 0.
- Check the wall type. Double walls count two wythes. Cavity width and ties are project-specific and not included in material volumes.
- Tune the dry:wet factor. Job-mix moisture, sand bulking, and waste handling cause the dry volume to exceed the wet volume. If your supplier recommends a factor, use it.
- Round up. Order a few more bricks than the math suggests, especially when color lots matter. A small surplus saves a second delivery.
Frequently Asked Questions
How many bricks are in 1 square foot?
It depends on the brick face size and the joint. For US nominal 8×4 in brick with a ⅜ in joint, the coverage per brick (including the joint allowances) is roughly (8 in + ⅜ in) × (4 in + ⅜ in). Convert to ft² and divide 1 ft² by that coverage to get bricks per square foot. The calculator does this automatically in any unit.
What wastage percentage should I use?
A default of 5% is a common planning allowance for breakage and cutting. Complex patterns, tight site logistics, or fragile glazed brick might justify a higher number. Always check your contractor’s recommendation.
What mortar mix ratio should I choose?
Follow the project specification or local code requirements. ASTM C270 defines mortar types by property and proportion. For general interior brickwork a 1:5 or 1:6 volumetric ratio is common. Exterior or structural applications often use richer mixes. When in doubt consult your designer or supplier.
What’s the difference between single and double wall?
A single wall has one wythe of brick. A double wall has two wythes used together; sometimes with insulation or an air cavity between them. The calculator multiplies the brick area by two when you select double. It doesn’t add a cavity or ties.
Can I mix units?
Yes. Enter length and height in ft/in if you like, and brick dimensions in inches. The tool converts everything internally so your totals are consistent.
How do I include doors and windows?
Subtract their area from the wall area before you calculate. For example, a 3 ft by 7 ft door removes 21 ft² from the wall. If your wall has several openings, sum them and subtract once.
Is the cement density fixed?
No. The default of ~90 lb/ft³ (~1440 kg/m³) is a planning value seen in many supplier sheets, but manufacturers publish their own densities. If you have a product data sheet, use those numbers and you’ll get a more precise bag count.
Step-by-Step: Using the Brick Calculator
Here’s a quick walk-through you can follow on any project. It reads like a checklist so you don’t miss a setting.
- Choose the wall type. Single for one wythe, double for two. If you’re building a sandwich wall with insulation in the middle, select double but remember the tool doesn’t include the cavity.
- Enter wall size. Fill length and height, or type a total area. If you use length and height the calculator fills the area for you. You can work in ft and in, metric, or a mix.
- Confirm brick details. Use the values from the manufacturer. In the US, the defaults (ℓ = 8 in, h = 4 in, w = 4 in, t = ⅜ in) are common. Different brick modules exist—adjust as needed.
- Read the brick count. You’ll get the whole-brick order quantity with wastage added. If the number looks high, double-check the joint setting and wall type.
- Open the mortar section. Toggle “show mortar” to see wet and dry volumes. Leave the dry:wet factor at 1.52 unless your supplier recommends something else.
- Pick a mix ratio. 1:6, 1:5, 1:4, or 1:3. The calculator splits the dry volume into cement and sand automatically.
- Set cement density and bag size. If you’re in the US, 90 lb/ft³ and 110-lb bags are common defaults. Enter product-specific values for best results.
- Add costs. Type the price per brick, price per bag, and sand price per unit. Select your currency and you’ll see a clean summary.
Why this method is dependable
Instead of memorizing “bricks per square foot” charts that only fit a narrow set of bricks, this calculator works from first principles. It uses the face dimensions plus joint to determine coverage. Then it computes mortar by volume, not a fixed percentage, so your numbers reflect the actual wall thickness and the brick count. The approach aligns with how builders measure work on site and how suppliers quote materials.
Example scenarios
A few quick sketches show how flexible the tool is.
Thin veneer over framed wall
Set wall type to single. Use the veneer brick’s specified face size and thickness (often ~2¾ in to 3⅝ in). Enter the typical joint. Mortar volumes will be smaller than a structural wythe because the thickness w is thinner.
Garden wall with coping
Calculate the wall body as usual. For the coping course you might choose a different brick or stone size. Run a second calculation just for the coping and add the totals together.
Metric project
Switch units to mm or cm and enter the exact numbers from the product sheet. The calculator converts internally and returns quantities in your chosen output units (m³, ft³, etc.).
Troubleshooting odd results
- Brick count is unusually high. Check that you didn’t enter both nominal sizes and a nonzero joint. If the face size already includes the joint, set t to zero.
- Mortar looks too low. Confirm the wall width w. A 3½ in thin veneer will use much less mortar than a full 4 in wythe.
- Bag count jumps when I switch density units. Make sure the density matches the units. 90 lb/ft³ is about 1440 kg/m³. If you enter 90 kg/m³ by mistake the weight will be far too low.
Glossary
- Wythe: a single continuous layer of bricks one unit thick.
- Bed joint: horizontal mortar joint between courses.
- Perpend: vertical mortar joint between bricks in the same course.
- Nominal size: the unit size plus an allowance for mortar joint thickness.
- Specified size: the actual manufactured unit size excluding joints.
A well-built wall starts with a solid plan. Use the brick calculator to turn rough sketches into material lists you can price and schedule. Double-check dimensions, choose the right mix, and round up for waste. You’ll order the right amount the first time and you’ll keep the project moving.
