Fundamental to standard UK interior door sizes is a 1981 mm x 762 mm slab, or put into imperial units, “2’6” x “6’6” slab, perfectly catering for width and accessibility and accordingly why it’s so frequently selected for English and Welsh dwellings.

The 2040 mm tall series is an incredibly popular choice for Scottish new-builds and many other UK regions, largely because of its modern-day and lofty look and feel. Most of the series contain widths including 726mm, 826mm and 926mm.

So that you can quickly compare sizes, the below chart pairs up imperial and metric labels with where each size is typically employed.

You will quickly learn how wide-ranging window sizes can be (the same with the best door colours), and it’s no different with doors. For instance, a bi-folding door’s size will always be greatly different from a conventional front door.

The function of each of these doors couldn’t be more opposite, with a bi-folding door largely about opening homes to gardens, rather than principally being a protective barrier.

Being wise to UK standard door sizes for each available door keeps you clued up on designs, removes any complications with installation, and makes the decision-making process easier.

Double doors, or if you like, paired doors, usually measure from 915 mm (3 ft) up to around 1512 mm (just under 5 ft) and boast a typical height of 1981 mm (6 ft 6 in).

They’re popularly employed in large interior openings and expansive entrances, needing two equally matched sections for balanced symmetry.

French doors are an undisputed classic and practical with it. The average thickness of internal French doors is about 35-40mm, while external French doors are marginally thicker at 44 mm for enhanced insulation and security.

Standard door width UK commands sizes ranging from 36 in (approx. 914mm) to 60 in (approx. 1524 mm) for successful integration into period cottages and broad patio openings. Some customers ask to have side panels to increase the glazed section and amplify natural light gain.

Sliding and bi-folding doors are all differently configured, so overall standard door sizes depend on the number of panels chosen and the width of the final opening.

A simple two-panel sliding door could measure around 1800 mm wide, whereas a bi-folding door consisting of seven panels can cover a distance of 6400 mm. The door setup must correspond to the aperture width, considering the amount of stacking space needed.

There are two common garage door sizes in the UK, consisting of 1981 mm x 2134 mm (6 ft 6 in × 7 ft) and 2134 mm × 2134 mm (7 ft × 7 ft). These complement the majority of single garages and are ordinarily found in up-and-over and sectional designs.

Side garage doors can be subject to building regulations as fire exits or escape routes, particularly if they’re the only alternative access point into a property.

Fire doors are an essential security feature and therefore have regulated sizing. Imperial fire door widths are commonly 27 in, 30 in and 32 in, while metric sizes tend to obey a 2040 mm height standard with widths of 626 mm, 726 mm, and 926 mm.

Frame setup is also dictated by fire ratings such as FD30 (30 minutes) and FD60 (60 minutes). To achieve compliance, intumescent seals, correct frame clearances and certified ironmongery are required.