How Many Roof Tiles Do You Need For A 3 Bedroom House

How Many Roof Tiles Do You Need For A 3 Bedroom House

roofers on roof

How Many Roof Tiles Will I Need For My Three-Bedroom House?

The number of roof tiles needed for a three-bedroom house can vary on a lot of different factors such as the size and shape of the roof, the type of tiles being used and any other additional features such as if your roof includes a chimney or windows.

As a rough estimate, the amount of tiles you will require for a three-bedroom house is around 2,000 – 4,000 tiles however this number can vary extremely based on the factors we have mentioned.

Throughout this article we will dive into how you can work out the exact number of roof tiles you will require for your three-bed home, as well as factors to consider when purchasing your new roof tiles so that you can find the perfect ones for your three-bed home.

As a leading roofing contractor in Melksham, we have a wide array of experience in installing and repairing roofing tiles for three-bedroom homes. For this reason, throughout this guide, we will include expert tips and tricks that we use to help you identify how many tiles you will need for your three-bed home.

Looking to replace or repair your roof? Here at A L King Roofing, we are the leading roofing company in Wiltshire and surrounding areas. Call us on 01225 705918.

How Do I Work Out How Many Roof Tiles I Need For A Three-Bedroom House?

There are three ways you can work out how many roof tiles you need for a three-bedroom house. To do this you must first calculate the area of your roof. From here you will need to determine the pitch of your roof and the rafter length.

This will allow you to determine the entire tile coverage. This will give you the exact number of tiles you will need for your roof. From here you will need to consider overlapping tiles and factor in a wastage percentage in order to calculate the total altogether so you aren’t short.

Throughout this article, we will provide you with the formulas and calculations you will need to determine the number of tiles you will require for your roof.

How To Calculate Your Roof Area

First and foremost to work out the number of tiles you will require for your three-bedroom house, you will need to work out the roof area.

To do this, please follow the formula below:

  1. Break Down the Roof into Sections: If your roof has a simple shape, such as a single rectangle or square, you can measure the length and width of the entire roof. However, if your roof is more complex, with multiple sections or different shapes, break it down into smaller, more manageable sections.
  2. Measure the Length and Width: For each section of the roof, use a tape measure to measure the length and width. Measure from the eaves (the lower edge of the roof) to the ridge (the highest point where the sections meet) for the length, and from one side of the roof to the other for the width. Record these measurements in feet.
  3. Calculate the Area of Each Section: Once you have the length and width for each section, multiply them together to find the area of each section in square feet. The formula for calculating area is:
    Area = Length × Width
  4. Add Up the Areas: If you have multiple sections, add up the areas of each section to find the total roof area. This will give you the overall size of your roof in square feet.

As an example, we used a three-bedroom home:

  1. Measure the Length and Width: Assume the dimensions of the main roof section are 30 feet in length and 20 feet in width. Additionally, let’s say there’s a smaller section, like a garage, with dimensions of 20 feet in length and 15 feet in width.
  2. Calculate the Area of Each Section:
    • Main Roof Section: Area = Length × Width = 30 ft × 20 ft = 600 sq.ft.
    • Garage Roof Section: Area = Length × Width = 20 ft × 15 ft = 300 sq.ft.
  3. Add Up the Areas: Main Roof Area + Garage Roof Area = Total Roof Area
    600 sq.ft. + 300 sq.ft. = 900 sq.ft.

How To Work Out The Pitch Of Your Roof

Once you have worked out the area of your roof, you now need to account for the pitch of your roof. To do this, please follow these steps:

  1. Measure the Run: Use a tape measure to determine the horizontal length between the peak of your roof and the wall. This measurement represents the run of your roof.
  2. Calculate the Rise: Use a tape measure to find the height of your apex above the wall structure. This measurement represents the rise of your roof.
  3. Calculate the Tangent: Divide the rise by the run to find the tangent of the roof’s slope. This is done by dividing the rise by the run (rise ÷ run = tangent).
  4. Use Trigonometric Functions: To convert the tangent to degrees, utilize trigonometric functions. The arctangent (inverse tangent) function is commonly used for this purpose. The formula is: Pitch Angle (in degrees) = arctan (rise ÷ run)
  5. Calculate the Pitch Angle: Input the rise and run values into the arctangent function on a calculator to find the pitch angle in degrees. The resulting value will give you the pitch angle of the roof.

If you would like to learn more about how to work out the pitch of your roof, please read our guide.

How To Calculate Rafter Length

Finally, you will need to work out the rafter length. To do this simply follow the guide below:

  1. Measure the Horizontal Run of the Rafter: The horizontal run is the distance along the bottom edge of the rafter from the wall to the outside edge of the roof. Measure this distance accurately using a tape measure.
  2. Calculate the Vertical Rise of the Rafter: The vertical rise is the height of the rafter from the top of the wall to the peak of the roof. This can be calculated by multiplying the horizontal run of the rafter by the pitch ratio. For example, if the pitch is 4:12 and the horizontal run is 10 feet, the vertical rise would be (4/12) × 10 feet = 3.33 feet.
  3. Use the Pythagorean Theorem: Once you have the horizontal run and vertical rise, you can use the Pythagorean theorem to calculate the length of the rafter. The formula is:
    Rafter Length = √(Horizontal Run² + Vertical Rise²)
    Plug in the values you’ve measured to find the length of the rafter.
  4. Account for Overhang: If your roof has an overhang, you’ll need to add the length of the overhang to the calculated rafter length to ensure the rafter extends past the edge of the roof.

How To Calculate The Amount Of Tiles

From here you can then use this information to work out the amount of tiles you will require by using the following method:

Number of Tiles = (Area Covered by One Tile x Rafter Length) / (Total Roof Area x Pitch Factor)

Factors To Consider When Ordering Tiles

As one of the leading roofing merchants in Melksham and the surrounding areas, we are no strangers to the pros and cons of each material and type of roofing tile. For this reason, we have created a list of factors you should consider when purchasing new roof tiles for your home renovation.

Now that you have worked out the amount of roof tiles you require for your roofing project, you should now think about the following factors:

  1. Material: There are various roofing tile materials available, each with its own advantages and disadvantages. Common options include clay, concrete, metal, and asphalt.
  2. Climate: The climate of your region plays a significant role in determining the most suitable roofing tiles. For example, in areas prone to high winds or storms, you may need tiles that are rated for high wind resistance. In regions with extreme temperatures, you might prioritize tiles that offer good insulation properties.
  3. Style and Aesthetics: Roofing tiles contribute significantly to the overall appearance of your home. Choose tiles that complement the architectural style of your house.
  4. Cost: Roofing tiles come in a wide range of prices, so it’s essential to consider your budget when making a selection. Keep in mind that while some materials may have a higher upfront cost, they could save you money in the long run due to their durability and energy efficiency.
  5. Installation Requirements: Different roofing materials have varying installation requirements, and some may be more complex or labour-intensive than others.
  6. Longevity and Maintenance: Evaluate the lifespan and maintenance needs of the roofing tiles you’re considering. Some materials require regular upkeep, such as cleaning or sealing, to ensure they remain in top condition. Others may offer better longevity and require minimal maintenance, which can be beneficial in the long term.

With all this in mind, you should now have a clear and concise idea of what is required for your roofing renovation and how you can pick the perfect tile to ensure that it is durable, long-lasting and most importantly protective of the property from the harsh weather conditions it will face 24 hours a day, 7 days a week.

If you are unsure of the best type of roofing tile for your property in Melksham or surrounding areas, please speak to one of our roofing experts on 01225 705 918 or visit our roofing merchants centre in Melksham.


As mentioned throughout this article, although the rough answer to how many roof tiles you will need for a three-bedroom home is 2,000 – 4,000 tiles, it is extremely important you do all the calculations to ensure you get the exact correct amount.

By working out the roof area, the pitch of your roof and the rafter length, you can work out the exact amount of tiles you will require for your roof. From here you will need to ensure that you account for an overlap for each tile of around 10 – 15% for each tile. In addition to this, you will also need to consider wastage due to cutting tiles to fit around edges, valleys and other roof features. Depending on the complexity of your roof design you may need to add an extra 5-10% to your tile count.

These factors are important to consider as well as working out the total amount in order to ensure you purchase the correct amount of tiles for your roof.

If you live in the Melksham, Bath or Bristol area, here at A L King Roofing, we provide a reliable, affordable and high-quality roof repair service. Originally starting out in 1979, A L King Roofing has over 40 years of experience in the roofing industry from repairs and new roof installations

Furthermore, we even provide a selection of high-quality roofing materials such as different roofing shingles and replacement shingles which you can find in our roofing merchants centre in Melksham. Speak to a member of the team on 01225 705 918 and discuss all your roofing requirements.

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