Brick Calculator
About Brick Calculation
The calculator estimates the number of bricks required for masonry walls, partitions, and gables, and can also determine mortar volume, approximate masonry weight, and linear loads when needed. This type of calculation is used for preliminary material purchasing, checking masonry volume, and comparing options by wall thickness, brick size, and building layout.
The calculation is suitable for typical rectangular and composite plans where the masonry area can be defined from geometric dimensions. The calculation logic is based on brick dimensions, joint thickness, wall thickness expressed in bricks, wall height, opening area, and selected additional options.
Reference points and recommendations
Masonry geometry
Perimeter and wall lengths. First, the calculator determines the total length of external walls based on the selected plan layout. Internal walls and partitions are calculated separately. If load-bearing wall C is included, it is treated as an external wall by thickness and is included in the calculation as a load-bearing element.
Wall area. The area of external masonry is determined as L × H, where L is the length of the corresponding walls in mm and H is the wall height in mm. After conversion to m2, window and door openings are subtracted from the external wall area. Partition area is calculated separately, and when this option is enabled, only door openings are subtracted from it.
Gables. If gable calculation is enabled, their area is determined as the area of a triangle: S = B × H × n / 2, where B is the width, H is the height, and n is the quantity. The gable area is then added to the total masonry area.
S = Sext - Sopenings + Sload-bearing C + Spartitions - Spartition doors + Sgables
Wall thickness and masonry module
Brick dimensions. The calculation uses the actual brick dimensions L × W × H in mm. External walls and partitions may use the same or different brick sizes. The volume of one brick is calculated without joints, using only its own dimensions.
Joint thickness. Joint thickness is included in the masonry module. A common default value is 10 mm, but the calculator uses the value entered by the user.
Wall thickness. Masonry thickness in mm is not taken as a fixed reference value. It is calculated from the brick size and joint thickness. The following rules are applied for the selected options:
0.5 brick = W1 brick = L1.5 bricks = L + W + joint2 bricks = 2L + joint2.5 bricks = 2L + W + 2 × joint
Here L is the brick length in mm and W is the brick width in mm. This calculated thickness in mm is then used for masonry volume, mortar, weight, and loads.
Brick quantity
Masonry module. For brick quantity, the calculator uses not the net brick size but the module based on face area. For external walls, the module of one brick is defined as (L + joint) × (H + joint). For partitions with a different brick, a separate module is used.
Converting thickness into quantity. For wall thicknesses made up of several half-brick layers, a bonding coefficient is applied. For 0.5 brick the coefficient is 1, for 1 brick it is 2, for 1.5 bricks it is 3, for 2 bricks it is 4, and for 2.5 bricks it is 5. This means the area-based calculation is multiplied by the number of half-brick layers in the wall thickness.
Main formula. The brick quantity for each group of elements is calculated from their masonry area divided by the module of one brick by face area, then multiplied by the thickness coefficient. Walls, partitions, and gables are calculated separately, and the results are then added together.
N = S / ((L + joint) × (H + joint)) × k
Where N is the brick quantity in pieces, S is the area of the corresponding masonry in m2, and k is the thickness coefficient. After that, wastage is applied: Ntotal = ceil(N × (1 + wastage/100)).
Masonry volume, brick volume, and mortar
Masonry volume. The total masonry volume is calculated as the area of each group of elements multiplied by the corresponding thickness in meters. External walls, partitions, and gables are calculated separately and then summed.
Vmasonry = S × t
Brick volume for purchase. After the final brick quantity with wastage is determined, the calculator multiplies that quantity by the volume of one brick without joints. Therefore, the result in m³ of bricks for purchase differs from the volume of finished masonry.
Mortar volume. Mortar is determined as the difference between the volume of finished masonry and the total volume of bricks within that masonry, after which wastage is also applied to the mortar. In other words, mortar joints are not estimated by a generalized coefficient but by the remaining volume between the bricks.
Vmortar = (Vmasonry - Vbricks in masonry) × (1 + wastage/100)
Mortar composition. If cement and sand calculation is enabled, the mortar volume is divided according to the entered mix proportion. The conversion to weight uses densities of 1400 kg/m³ for cement and 1600 kg/m³ for sand.
Reinforcement
Number of courses. The number of masonry courses is determined from the wall or partition height and the course module: H + joint. The calculator applies rounding up, so an incomplete top course is still counted.
ncourses = ceil(Height / (Hbrick + joint))
Reinforcement spacing. If reinforcement is set at every Nth course, the number of reinforced courses is calculated as floor((ncourses - 1) / N) + 1. This means the first reinforced course is also included in the result.
Reinforcement under windows. When opening consideration is enabled, the calculator additionally adds reinforcement length below windows. For each window, 1000 mm is added to its width, which means 500 mm extension on each side.
Mesh and reinforcing bars. For mesh, the total strip length is calculated first, then mesh area as length × wall thickness. For reinforcing bars, the calculator determines the total length, the number of bars in each reinforced course, and the weight using steel density 7850 kg/m³.
Weight and loads
Brick weight. Brick weight is determined from the entered material density in kg/m³ and the total brick volume. Different densities may be used for walls and partitions if the bricks are different.
Mortar weight. In the load section, mortar weight is determined using an assumed density of 2000 kg/m³. The brick weight and mortar weight are then added together.
Linear load. For load-bearing walls and partitions, the calculator divides the corresponding part of the total weight by the total length of those walls. The result is shown in kN/m. To convert mass into force, the factor 9.81 m/s2 is used.
q = G × 9.81 / L
Mortar distribution. Mortar weight is distributed between external walls and partitions in proportion to their masonry volume. This means the linear load includes not only the bricks but also the corresponding share of mortar.
Normative references
Brick masonry. The logic of masonry geometry and brick quantity follows the general design principles for masonry structures in Eurocode 6, primarily EN 1996-1-1 Design of masonry structures. General rules for reinforced and unreinforced masonry structures and EN 1996-2 Design considerations, selection of materials and execution of masonry.
Loads. The weight and load section follows the general approach to permanent actions in EN 1991-1-1 Eurocode 1. Actions on structures. General actions. Densities, self-weight, imposed loads for buildings. For working documentation and structural verification, these values are usually refined according to the actual construction, mortar, facing, reinforcement, and adopted structural scheme.
FAQs
Why is brick quantity calculated not only from brick size but also from joint thickness?
Because in real masonry, bricks are separated by mortar joints, and the masonry module is what determines how many bricks fit into 1 m2. If joint thickness is ignored, the estimated brick quantity will be overstated.
Why is the brick volume for purchase smaller than the masonry volume?
Masonry volume includes both bricks and mortar in the joints. Brick volume for purchase is only the net volume of the bricks themselves without mortar, so it is always smaller than the volume of finished brick masonry.
Why is wastage needed if the brick calculation is already precise?
Even a precise brick calculator does not account for breakage, cutting, special pieces, and local losses on site. For that reason, wastage is commonly used in practice, and its value depends on wall complexity and workmanship quality.
Why does the linear wall load depend not only on brick density but also on mortar?
Because the self-weight of masonry consists of two parts: the weight of the bricks and the weight of the mortar joints. If only the bricks are considered, the calculated load on the slab or foundation will be underestimated.
Can this brick calculation be used for a final estimate and project documentation?
For preliminary material purchasing and option comparison, this calculation is usually suitable. For final design and a precise estimate, the values should be checked against working drawings, the bonding pattern, actual opening dimensions, and the requirements of the Eurocodes for masonry structures.