Brick Calculator: Wall Bricks, Blocks, Cement and Sand
Estimate bricks or AAC blocks, cement bags and sand after deducting openings. Compare mortar, wall weight and your material costs with regional sizes and custom dimensions.
This brick calculator estimates the units and joint materials for a straight rectangular wall. Engineers, students, quantity surveyors and homeowners can use it for an initial material take-off, a classroom calculation or a comparison of local supplier quotes. It covers red clay bricks, fly ash bricks and AAC blocks, with openings deducted before quantities are calculated.
Enter the wall length and height, then add a rectangular opening if needed. The drawing centres that opening horizontally; a sill height of zero represents a door. Enter the total area of any other non-overlapping openings separately. Those additional deductions affect quantities but are not drawn. Choose the material whose results you want on the main cards.
The size lists include Indian modular 190 mm bricks, UK metric 215 mm bricks, US modular bricks and several AAC widths. Select Custom in a size field to enter your supplier's actual length, width and height. Dimensions exclude mortar. The number of solid leaves sets the wall thickness: one leaf is one unit width; additional leaves have a filled joint between them. This model covers solid construction rather than a cavity wall.
To find how many bricks in 100 sq ft, read the coverage table. It shows full-unit equivalents before wastage for both square metres and 100 square feet. Coverage changes with unit size, joint thickness and the number of leaves. The order quantity adds your unit allowance and rounds up once. It is an estimate, not a cutting schedule or an exact count of the bricks drawn.
For site-mixed mortar, enter the cement-to-sand volume ratio, wet-to-dry factor, cement bulk density and bag mass. The calculator reports whole cement bags and loose dry sand, including a separate joint-material allowance. In AAC block calculator mode, choose either ordinary mortar or thin-bed adhesive. Preblended adhesive uses its mixed yield per bag; its ingredients are not counted again as separate cement and sand. Allow separately for a levelling bed at the first course.
The comparison uses the same net elevation area and leaf count for all three options. Check their displayed thicknesses before comparing cost or weight. Enter current supplier prices in one currency; zero prices exclude those items and leave a partial quoted subtotal. No market prices or exchange rates are assumed.
Wall mass excludes purchasing wastage and finishes. The line load averages that mass over the gross wall length; it is not a slab reaction or a structural adequacy check. Moisture, frogs, filled cores, reinforcement, lintels, ties, plaster, foundations, labour and delivery can change the real quantities or loads. Have the wall specification and supporting structure checked for the actual project, and use qualified people for masonry installation.
How it is calculated
The wall-area take-off follows the approach described in BIA Technical Note 10 (February 2009), p.8, with equations derived here for rectangular units in running bond. For each option, actual unit dimensions are length , width through wall , height , equal bed/head joint and solid leaves.
The calculation evaluates the last expression as leaf bed/head joints plus filled collar joints to avoid cancellation at zero joint thickness. BIA TN10 p.10 Table 5 independently supplies collar-joint volumes. Counts use fractional full-unit equivalents; only ordering is rounded up after allowance. Boundary cuts and bond details require a separate take-off.
For site mortar, , cement volume is , cement mass is that volume times loose bulk density, and sand volume is . Divide cement mass by bag mass and round up. The editable factor is a site-estimating convention, illustrated by Ministry of Labor and Skills, Measurement and Quantity Estimation (2022), p.36; it is not a universal mortar yield.
Thin-bed AAC uses the joint volume divided by the selected mixed yield per adhesive bag, including joint-material allowance. White Sand FIX LB supplies the example 14 L per 20 kg bag and mixed density 1700 kg/m³. No cement/sand split is applied to adhesive.
Installed mass is gross unit volume times bulk unit density plus installed joint volume times joint density. Weight uses standard gravity 9.80665 m/s². Average line load divides by the gross wall length. Costs use ordered whole units, ordered whole bags and loose sand volume, with every price entered by the user.
The installed-quantities table uses the installed joint volume before any allowance to report consumed cement and adhesive bag equivalents. Purchasing tables apply the joint-material allowance and then round whole bags up.
Assumptions
- Straight rectangular wall, rectangular units laid flat, running bond, full bed and head joints. One common joint thickness per option; no header courses or bond-pattern multiplier.
- Multiple leaves are adjacent solid leaves with fully filled collar joints, not a cavity wall. Comparisons keep the same net area and leaf count; actual wall thickness can differ.
- Openings are clear rectangular areas with no overlap. Extra opening area excludes the opening drawn. No regulatory measurement-rule deductions or minimum-opening exemptions are applied.
- Dimensions are size examples from the attached sources. Custom dimensions require the supplier's actual sizes. The drawing is an original schematic; dense patterns are simplified and boundary cuts do not constitute a laying schedule.
- Density defaults are examples: red brick 1950 kg/m³ and AAC 600 kg/m³ from Suryshree's published comparison; fly ash 1800 kg/m³ within Yoddha's 1700–1850 range. Loose cement 1440 kg/m³ and installed site mortar 2000 kg/m³ are editable estimating assumptions, not measured project properties. Use bulk unit density including voids or derive it from measured unit mass.
- AAC density is oven dry. Actual wet blocks can be heavier. The adhesive example uses a mixed density; wall mass is therefore a stated material estimate rather than an exact long-term dry mass.
- Unit allowance and mortar allowance are independent percentages added to theoretical need. Neither surplus contributes to installed wall mass.
- Quoted costs are in one currency and use current user-entered prices. Zero means unpriced/excluded, not free. No market price, tax rule or currency conversion is assumed; prepared 26 October 2026.
- US modular preset: actual 7⅝ × 3⅝ × 2¼ in. With equal ⅜ in bed and head joints, geometric coverage is 685.7 units/100 ft². The familiar 675 figure uses the nominal 8 × 2⅔ in face module, which does not equal those actual dimensions plus equal ⅜ in joints. This calculator keeps the entered geometry rather than forcing a nominal rule of thumb.
Where it applies
Use for preliminary material quantities in solid brickwork and AAC blockwork. It does not design wall strength, stability, restraint, wind or seismic resistance, mortar grade, or a supporting slab.
Gross unit envelopes are subtracted from the wall envelope. Additional mortar entering frogs, perforations or cores, face-shell bedding, hollow concrete block grout, nonrectangular units, raked/decorative joints, special bonds, piers, corners, returns and concentrated bearing loads require separate allowances or a different model. First-course levelling beds, lintels, sills, ties, reinforcement, plaster and finishes are excluded.
The average line load is not the pressure on the slab: openings and lintels redistribute load locally. Use actual service moisture, finishes and structural reactions for slab design. Check unit sizes, joint specifications, adhesive compatibility and yield against the manufacturer and the standard in force. BIA's fired-clay construction guidance is not used here to claim performance of fly ash or AAC products. Masonry installation belongs to qualified people.
References
- BIA, Technical Note 10, Dimensioning and Estimating Brick Masonry, February 2009, pp.4,8–10. https://www.gobrick.com/media/file/10-dimensioning-and-estimating-brick-masonry.pdf
- Michelmersh, Selected Light: 215 × 102.5 × 65 mm; 60 products/m² (rounded coverage). https://www.mbhplc.co.uk/products/selected-light/
- UltraTech, Types of Bricks & Their Properties: Indian modular 190 × 90 × 90 mm. https://www.ultratechcement.com/for-homebuilders/home-building-explained-single/descriptive-articles/types-of-bricks-and-its-properties
- Hira Group, Fly Ash Products: 190 × 90 × 90 and 230 × 110 × 75 mm. https://www.hiragroup.com/products/products/fly-ash-products/
- Suryshree Blocks, technical specification: 600 × 200 mm AAC faces, 75–225 mm widths, dry density 550–650 kg/m³ and clay-brick comparison density 1950 kg/m³. https://suryshreeblocks.com/tech-specification/
- Yoddha, Fly Ash Brick Brochure: approximate density 1700–1850 kg/m³. https://yoddhagroup.com/uploads/brochure/Paver_Block__Fly_ash_brick_Brochure.pdf
- White Sand, FIX LB Lightweight Block Adhesive: approximately 14 litres mixed yield per 20 kg bag, wet density approximately 1.7 kg/L. https://www.whitesand.sa/products/tiling-systems/white-sand-fix-lb/
- Ministry of Labor and Skills, Measurement and Quantity Estimation, April 2022, p.36: wet-to-dry mortar factor 1.33, a site estimating convention. https://www.hptc.edu.et/sites/default/files/2023-02/Download_66.pdf
- Magicrete, AAC Block Sizes & IS Standards Explained, face coverage chart: 0.12 m² and 8.33 blocks/m² before joints. Chart weights are inconsistent with its stated density and are not used. https://www.magicrete.in/blog/aac-block-size-and-is-standards
Inputs
| Input | Symbol | Unit | Default |
|---|---|---|---|
| Wall length | L_wall | m | 5 |
| Wall height | H_wall | m | 3 |
| Deduct a rectangular opening | has_opening | true | |
| Opening width Shown centred horizontally; set sill height to zero for a door. | W_open | m | 1.2 |
| Opening height | H_open | m | 1.2 |
| Opening sill above base | Y_open | m | 0.9 |
| Other openings to deduct Total additional, non-overlapping opening area. These extra openings are not drawn. | A_extra | m^2 | 0 |
| Solid leaves across thickness 1 = a half-brick leaf or one block width. Leaves touch through filled mortar joints; this is not a cavity wall. | n_leaf | 1 | |
| Result and drawing material All three options are compared below for the same net area and number of solid leaves. | material | Red / clay brick | |
| Red brick size Actual length × width through wall × height, excluding joints. Use Custom for your supplier's dimensions. | red_size | Indian modular | |
| Fly ash brick size Actual length × width through wall × height, excluding joints. Use Custom for your supplier's dimensions. | fly_size | Indian modular | |
| AAC block size Actual length × width through wall × height, excluding joints. Use Custom for your supplier's dimensions. | aac_size | AAC 100 | |
| Red brick joint thickness Bed and vertical joints equal. For US modular with 3/8 in joints enter 9.525 mm. | j_red | mm | 10 |
| Fly ash joint thickness | j_fly | mm | 10 |
| AAC jointing material | aac_binder | Thin-bed block adhesive | |
| AAC thin-bed joint Use the block and adhesive manufacturer's specified joint. | j_thin | mm | 3 |
| AAC cement mortar joint | j_aac | mm | 10 |
| Sand parts per 1 cement part Loose dry volume ratio 1 : this number. This estimates quantities; it does not specify mortar strength. | sand_parts | 6 | |
| Wet-to-dry volume factor Site estimating allowance for loose cement and sand; not used for preblended adhesive. | f_dry | 1.33 | |
| Units allowance (%) Extra units = theoretical count × this percentage, then round up once. | w_units | 5 | |
| Mortar / adhesive allowance (%) Applied to joint material only; excluded from installed wall mass. | w_mortar | 10 | |
| Cement bag mass | m_bag | kg | 50 |
| Adhesive bag mass White Sand FIX LB example: 20 kg bag. | m_adhbag | kg | 20 |
| Mixed adhesive yield per bag White Sand FIX LB example: 14 litres of mixed adhesive per 20 kg bag. Match yield to your selected bag. | Y_bag | L | 14 |
| Red brick density Bulk unit density including voids; replace with measured unit mass divided by gross unit volume. | rho_red | kg/m^3 | 1950 |
| Fly ash brick density Illustrative value within Yoddha's published 1700–1850 kg/m³ range. | rho_fly | kg/m^3 | 1800 |
| AAC density Oven-dry example; construction moisture can increase slab loading. | rho_aac | kg/m^3 | 600 |
| Installed mortar density Engineering estimate, not a measured project value. | rho_mortar | kg/m^3 | 2000 |
| Mixed adhesive density White Sand FIX LB published wet density, 1.7 kg/l. | rho_adh | kg/m^3 | 1700 |
| Loose cement bulk density For volume batching, not cement particle density. | rho_cement | kg/m^3 | 1440 |
| Red brick price per unit Enter current supplier prices in one currency. Zero excludes this item from the quoted subtotal. | p_red | 0 | |
| Fly ash brick price per unit Enter current supplier prices in one currency. Zero excludes this item from the quoted subtotal. | p_fly | 0 | |
| AAC block price per unit Enter current supplier prices in one currency. Zero excludes this item from the quoted subtotal. | p_aac | 0 | |
| Cement price per bag Enter current supplier prices in one currency. Zero excludes this item from the quoted subtotal. | p_cement | 0 | |
| Sand price per m³ Enter current supplier prices in one currency. Zero excludes this item from the quoted subtotal. | p_sand | 0 | |
| Adhesive price per bag Enter current supplier prices in one currency. Zero excludes this item from the quoted subtotal. | p_adh | 0 |
Results
With the default inputs above, the calc gives:
| Result | Value |
|---|---|
| Net wall area | 13.56 m² |
| Whole bricks / blocks to order | 712 |
| Whole cement bags to buy | 2 |
| Loose dry sand to order | 0.222 m³ |
| Whole AAC adhesive bags to buy | 0 |
| Installed wet joint material | 0.177 m³ |
| Estimated installed wall mass | 2,389 kg |
| Average wall line load | 4.68 kN/m |
| Quoted subtotal (0 = unpriced) | 0 |
| Units per m² before allowance | 50 m⁻² |
| Units per 100 ft² before allowance | 464.5 |
| Solid wall thickness | 90 mm |
Checked against sources
Each case below was calculated by this calc and agrees with the value from its source (within the tolerance where one is shown).
UK manufacturer: 60 bricks per m²
Source: Michelmersh Selected Light product data, https://www.mbhplc.co.uk/products/selected-light/ : 215 × 102.5 × 65 mm, 60 products/m². Published coverage is rounded to a whole brick; exact 10 mm module geometry gives 59.2593/m². Tolerance 0.8 covers published rounding, not an adjusted formula.
Inputs: Red brick size = UK metric; the others as above.
| Result | Source | This calc |
|---|---|---|
| Theoretical units per square metre [1] | 60 ± 0.8 m⁻² | 59.259 m⁻² |
BIA TN10: mortar in a 9.5 mm collar joint
Source: BIA Technical Note 10 (February 2009), p.10 Table 5: 0.095 m³ of collar-joint mortar per 10 m² at the stated metric 9.5 mm joint. This checks the solid collar volume independently of the face-module method.
Inputs: Wall height = 2 m; Deduct a rectangular opening = no; Solid leaves across thickness = 2; Red brick joint thickness = 9.5 mm; the others as above.
| Result | Source | This calc |
|---|---|---|
| Filled joints between solid leaves [1] | 0.095 m³ | 0.095 m³ |
AAC manufacturer: joint-free 8.33 blocks per m²
Source: Magicrete, AAC Block Sizes & IS Standards Explained, Quick Size Reference Chart, https://www.magicrete.in/blog/aac-block-size-and-is-standards : 600 × 200 × 100 mm, coverage 0.12 m², 8.33 blocks/m². The table is joint-free coverage; this case deliberately sets joint to zero. Its weight column conflicts with its density statement, so those weights are not used.
Inputs: Result and drawing material = AAC block; AAC thin-bed joint = 0 mm; the others as above.
| Result | Source | This calc |
|---|---|---|
| Units per m² before allowance | 8.33 m⁻² | 8.333 m⁻² |
Manufacturer adhesive mixed-volume yield
Source: White Sand FIX LB technical data, https://www.whitesand.sa/products/tiling-systems/white-sand-fix-lb/ : a 20 kg bag yields approximately 14 litres. This verifies the bag-yield volume conversion used to order adhesive.
Inputs: the default inputs above.
| Result | Source | This calc |
|---|---|---|
| Mixed adhesive yield of one bag | 0.014 m³ | 0.014 m³ |
Responses