## How to calculate the number of bricks in a wall

If you prefer to calculate the number of bricks you need to build a wall, you can use The Brick Calculator or you can work it out yourself using the following guide and formulas.

### Step 1 - Material measurements and wall requirements

The key to any successful building project is to take the time to plan through your exact requirements. This is particularly important when planning to build a wall as materials are expensive. If you over order, you will be left with a lot of building materials that you may not be able to dispose of cheaply if the builders merchant doesn't accept returns. If you under order, you face additional costs for delivery, lost labour time and delays to your project. When planning to build a wall, the following information is essential for calculating how many bricks you will need for your new wall.

- Length of the wall
- Height of the wall
- The size of the bricks you will use (length, height and width)
- The thickness of the mortar
- Whether the wall will be single skinned (1 brick wide, aka a 9 inch wall [22.86cm]), half brick thick (1.5 bricks wide, aka a 14 inch wall [35.56cm]), double skinned (2 bricks wide, aka a 18 inch wall [45.72]) or a two and a half brick wall (2.5 bricks wide, aka a 22 inch wall [55.88])

### Step 2 - Calculate the volume of one brick with mortar

In order to calculate the volume of your chosen brick for your new wall, you simply need to use the brick measurements you collected in Step 1. To keep this example simple, we will use a brick size of 19cm long, 10cm wide and 14 cm high and we will use a mortar thickness of 10mm (1cm).

We calculate the volume of the brick by multiplying the height, length and width of the brick (Volume = Length x Width x Height, though we use Length x Height X Width as this is common practice in industry as wall area, Length x Height, is typically calculated first when assessing a wall ) including the thickness of the mortar. We will calculate the volume in m^{3} so we will need to change our centimetres to metres. Lets look at our example:

#### Example: Calculate the volume of one brick with mortar

Brick Volume = Brick Length x Brick Height x Brick Width

Brick Volume = 19cm x 14cm x 10cm [Dimensions of one brick]

Brick Volume = (19cm + 1cm) x (14cm + 1cm) x 10cm [Dimensions of 1 brick with mortar: See note 1]

Brick Volume = 20cm x 15cm x 10cm [Dimensions of 1 brick with mortar ^{1}]

Brick Volume = 0.2m x 0.15m x 0.1m [Dimensions changed to meters]

Brick Volume = 0.2 x 0.15 x 0.1 [Dimensions without units shown for clearer calculation]

Brick Volume = 0.003m^{3} [Volume of one brick with mortar]

#### Notes for 'volume of one brick with mortar calculation example'

**1** In this brick calculation, we have added mortar to the top and one side of the brick. Some brick calculations and brick calculators add mortar to the width of the brick when calculating the volume of the brick with mortar. Our method provides greater accuracy when calculating the volume, the latter approach allows for more wastage. The Brick Calculator includes a wastage allowance in the materials list, we feel this provides greater control for material planning and costs.

### Step 3 - Calculate the volume of a single skinned wall

In order to calculate the volume of your wall, you will need the wall measurement collected in Step one. In our example wall, we will say the wall is 2m high and 5m long. If you have just completed step 2 and not jumped ahead, you will know we also need the width of the wall in order to calculate the volume of the wall. The width of our wall is the same width as the brick, in our example, our brick width is 10cm.

We calculate the volume of the wall by multiplying the height, length and width of the wall (Volume = Length x Width x Height).

#### Example: Calculate the volume of a single skinned wall

Wall Volume = Wall Length x Wall Height x Brick Width

Wall Volume = 5m x 2m x 10cm [Dimensions of the wall]

Wall Volume = 5m x 2m x 0.1m [Dimensions changed to meters]

Wall Volume = 5 x 2 x 0.1 [Dimensions without units shown for clearer calculation]

Wall Volume = 1m^{3} [Volume of a single skinned wall]

We have now calculated the volume of your wall at 1 brick thickness, if you were building a half brick wall, double skin wall etc. you would multiply the volume by the thickness of the wall required, let's look at an example of the various wall thicknesses mentioned and the associated volume for that thickness based on our single wall calculations.

#### Example: Multiple thickness wall examples

Volume = 1m^{3} [Volume of a single skinned wall]

Volume = 1.5m^{3} [Volume of a half brick thick wall]

Volume = 2m^{3} [Volume of a double skinned wall]

Volume = 3m^{3} [Volume of a two and a half brick wall]

### Step 4 - Calculate the number of bricks required to build a single skinned wall

Now that we have worked out the volume of one of our bricks with mortar and the volume of our single skinned wall we can calculate the number of bricks required to build our single skin wall.

We calculate the number of bricks required by dividing the volume of our wall by the volume of our brick with mortar (Number of bricks required = Volume of wall / Volume of 1 brick with mortar). Let's take another look at our example

#### Example: Calculate the number of bricks required to build a single skinned wall

Number of bricks required = Volume of wall / Volume of 1 brick with mortar

Number of bricks required = 1m^{3} / 0.003m^{3}

Number of bricks required = 1 / 0.003 [Volumes without units shown for clearer calculation]

Number of bricks required = 333.33 [Exact]

Number of bricks required = 334 [Rounded up: See note 1]

#### Notes for 'Number of bricks required calculation example'

**1** When calculating the number of bricks required it is always better to round up to the full brick. In the real world, the brick layer will build the wall evenly and the full brick will avoid lost time / additional cost if the brick is required. As we will proceed, we will review wastage allowances and tolerances for brick requirement calculations in more detail.

We have now calculated the volume of your wall at 1 brick thickness, if you were building a half brick wall, double skin wall etc. you would multiply the volume by the thickness of the wall required, let's look at an example of the various wall thicknesses mentioned and the associated volume for that thickness based on our single wall calculations.

#### Example: Calculate the number of bricks required to build multiple thickness walls

Number of bricks required = 334 [Single skinned wall]

Number of bricks required = 667 [Half brick thick wall]

Number of bricks required = 668 [Double skinned wall]

Number of bricks required = 1334 [Two and a half brick wall]

### Step 5 - Allowing for wastage

Realistically no one likes waste but with bricks it is certainly worth factoring in a wastage percentage. You may wonder why wastage is essential in planning your wall, here are several good reasons why wastage allowance is practical and a more efficient approach to a successful building project:

**Cosmetic**: Bricks can be discoloured/irregular and batch pigments can differ. Modern engineering and technology mean this is less likely with newer bricks but it remains a consideration, having a wall built is a costly expense, it is worth getting it right first time.**Breakages**: It is not unusual to have a number of split or damaged bricks when the bricks are delivered. If you call your supplier/builders merchant they will normally replace those free of charge. Bricks can however break during construction. Some bricks may need to be split to fit the aspect of the wall, not all bricks split well.**Alteration**: Any last minute changes to requirement (height, length) can be overcome with the flexibility of wastage.**Miscalculation**: When that gap you measured at 3 meters suddenly measures at 3.1 metres... an extra 10cm length against 2 metres of height on a double skinned wall is a fair few extra bricks.**Cost**: If you run out of bricks, you will be faced with the costs of transportation (delivery/collection), lost/additional labour time, higher cost per brick (bulk rates are typically lower) and/or supply issues.**Supply**: We can always buy more... well, that's not always true. Older bricks, Cheshire wire cut for example, can be tricky to source unless buying in bulk. Newer bricks can also prove tricky sometimes if a large building project suddenly ups demand and takes all existing stock and creates large back orders. This could leave your wall half built for several months or mean you travelling long distances to source existing matching brick stock.**Time**: Whatever the challenges associated with running out of bricks, one thing is for sure, it is going to create delays and mean less productive time. This in turn can cause frustration, particularly if your brick layer has a lot of other work lined up, you could find yourself waiting several weeks to get the job finished.

So, what is the best wastage tolerance to use. Well, this depends entirely on the size of your project. For brick requirement calculations on The Brick Calculator, we use a 5% wastage allowance, this is typical for a smaller project such as garden walls, small garage etc. If you are calculating the bricks required for a larger project (house construction etc.), you may wish to alter the wastage percentage to a lower figure like 5%. Whatever your wastage factor, always check with your builder merchant / brick supplier to see if they take returns. Most, but not all will take any unused bricks as long as they remain in good condition but you should always check. If you do end up with bricks you can't use, try selling them on eBay or a local free sales site, they will normally be snapped up and save you the bother of disposing of your unwanted bricks.