Door Size Guide: Do Doors Come In Different Sizes?

Whether you’re renovating your home, replacing an old door or working on a new-build project, understanding door sizes is crucial for a perfect fuss-free fit. Providing security, privacy and aesthetic appeal, the doors you choose will serve various different purposes from room-to-room in either a domestic or commercial setting. However, many homeowners and tradespeople often ask: do doors come in different sizes? 

The answer is yes, and the variety of sizes available can sometimes make choosing the right one a challenge…

Standard door sizes exist to ensure compatibility with most homes and buildings, but variations are common depending on the style, age, and purpose of the property. From standard internal and external doors to custom-made solutions, knowing the correct dimensions can save you time and money when purchasing or fitting a new door.

Failing to choose the right size door can lead to costly adjustments or installation difficulties. A door that’s too small may leave unsightly gaps, while one that’s too large may require excessive trimming, potentially weakening its structure. Understanding the available sizes will help you make an informed decision and ensure a seamless fit.

This Door Giant guide will explore the different door sizes available, standard dimensions in the UK, and what to do if your doorway doesn’t fit conventional measurements. Whether you’re looking for internal, external, or custom doors, this article will help you find the perfect size for your needs.

Standard UK Door Sizes

In the UK, standard door sizes have been established to ensure consistency across different properties.

The most common sizes for internal doors are:

• 1981mm x 762mm (6’6” x 2’6”) – The most common internal door size in UK homes.
• 1981mm x 838mm (6’6” x 2’9”) – A wider option, often used for improved accessibility.
• 1981mm x 686mm (6’6” x 2’3”) – A narrower door size, ideal for smaller spaces such as cupboards.

External doors are typically larger and more robust to provide security and weather protection.

The standard UK external door sizes are:

• 1981mm x 838mm (6’6” x 2’9”) – The most common size for front and back doors.
• 2032mm x 813mm (6’8” x 2’8”) – A slightly taller option, commonly found in newer builds.
• 2083mm x 864mm (6’10” x 2’10”) – Used in some commercial and modern residential properties.

While these are standard sizes, older buildings and custom projects may require bespoke solutions.

Custom & Made-To-Measure Doors

If your home doesn’t conform to standard door sizes, you may need a custom-made door. Many period homes, especially Victorian and Georgian properties, have taller or wider door frames that don’t fit modern dimensions. In such cases, made-to-measure doors are the best solution.

Custom doors allow homeowners to choose the exact dimensions required for their space, ensuring a perfect fit and preserving the character of older properties. These doors are also useful in contemporary designs where non-standard door sizes are used to create a striking visual impact.

However, bespoke doors often come at a higher cost due to the additional labour and materials involved. It’s important to weigh the benefits of a perfect fit against the increased expense.

How To Measure For A New Door

If you’re replacing an existing door, measuring accurately is crucial to avoid installation issues. Follow these steps:

1. Measure the height – Take three measurements from the left, middle, and right sides of the door frame, using the smallest measurement.
2. Measure the width – Again, measure at the top, middle, and bottom, recording the smallest size.
3. Check the door thickness – Most internal doors are 35mm or 40mm thick, while fire doors are typically 44mm.
4. Consider the frame – If the frame is not square, adjustments may be necessary to ensure the door fits correctly.

Taking precise measurements will help you choose the right door size and prevent unnecessary modifications.

What To Do If Your Door Frame Doesn’t Match Standard Sizes?

If your door frame doesn’t match standard dimensions, there are a few options available:

• Trimming a standard door – Many doors allow for slight adjustments, but excessive trimming can weaken the structure, especially in hollow-core doors.
• Using a door lining kit – These kits can help adjust the frame to accommodate a standard door size.
• Ordering a bespoke door – For the best fit, a made-to-measure door is the ideal solution, though it may cost more.
• Installing a door set – A pre-hung door set includes the frame and door, ensuring a perfect fit without the need for modifications.

Choosing the right approach depends on your budget, the amount of adjustment needed, and whether you want to preserve the door’s integrity.

Doors come in a variety of sizes, with standard dimensions available to suit most homes and buildings. However, custom and made-to-measure doors are often necessary for period properties or unique designs. Understanding the different sizes and how to measure correctly will help you select the right door for your needs.

If your doorway doesn’t match standard sizes, there are solutions available, including trimming, using door lining kits, or ordering a bespoke door. By taking accurate measurements and considering your options carefully, you can ensure a smooth installation and a professional finish.

Whether you’re replacing an internal or external door, being informed about door sizes will help you make the right choice. Ready to find the perfect door for your home? Start measuring today!