Standard Picture Frame Sizes: A Complete UK Guide

Knowing your standard picture frame sizes saves time, money, and a fair bit of guesswork. Ready-made frames and pre-cut mounts are built around a set of common dimensions, so if your artwork or print fits one of these, you can source materials quickly and affordably. If it does not, that is when bespoke framing comes in.

This guide covers all the standard frame sizes used in the UK, from A-series paper sizes to common photo print dimensions, with both metric and imperial measurements. Bookmark it for next time you need to check.

A-series paper sizes (ISO 216)

These are the most widely used standard frame sizes in the UK. If you have a print, poster, or certificate, chances are it was printed on one of these.

A0: 841 x 1189 mm (33.1 x 46.8 inches). A1: 594 x 841 mm (23.4 x 33.1 inches). A2: 420 x 594 mm (16.5 x 23.4 inches). A3: 297 x 420 mm (11.7 x 16.5 inches). A4: 210 x 297 mm (8.3 x 11.7 inches). A5: 148 x 210 mm (5.8 x 8.3 inches).

A4 and A3 are by far the most common for framing. Certificates, diplomas, and smaller art prints usually come in A4. Larger posters and limited-edition prints tend to be A3 or A2. Anything A1 or A0 is getting into oversized framing territory, where off-the-shelf options become scarce.

Standard photo print sizes

Photo print sizes in the UK follow a separate set of standard frame measurements, based on traditional photographic paper. These are always given in inches.

6 x 4 inches (15 x 10 cm). 7 x 5 inches (18 x 13 cm). 8 x 6 inches (20 x 15 cm). 10 x 8 inches (25 x 20 cm). 12 x 8 inches (30 x 20 cm). 12 x 10 inches (30 x 25 cm). 14 x 11 inches (36 x 28 cm). 16 x 12 inches (41 x 30 cm). 20 x 16 inches (51 x 41 cm).

The 6x4 and 7x5 are classic snapshot sizes. The 10x8 is the go-to for portrait photography and studio prints. Anything above 16x12 starts to overlap with A-series dimensions, and many framers will refer to the metric equivalent instead.

Imperial frame sizes commonly used in the UK

Alongside photo sizes, the UK framing trade uses a range of imperial standard picture frame dimensions that do not neatly match either A-series or photo prints. These crop up regularly for artwork and decorative prints.

8 x 10 inches (20 x 25 cm). 9 x 12 inches (23 x 30 cm). 11 x 14 inches (28 x 36 cm). 12 x 16 inches (30 x 41 cm). 16 x 20 inches (41 x 51 cm). 18 x 24 inches (46 x 61 cm). 20 x 24 inches (51 x 61 cm). 24 x 30 inches (61 x 76 cm). 24 x 36 inches (61 x 91 cm).

The 16x20 and 20x24 sizes are popular for gallery-style prints and original paintings. Many high-street frame shops stock these, though the range of moulding styles at those sizes tends to be limited.

Image size, mount opening, and frame size: what is the difference?

This catches people out more than anything else. When we talk about picture frame sizes, there are actually three different measurements in play.

The image size is the dimensions of your artwork or print itself. The mount opening is the window cut into the mount board that shows the image, typically slightly smaller than the image so the edges are held in place. The frame size is the overall external dimension of the frame, which depends on both the mounted image and the width of the moulding.

So a 10x8 inch print in a standard mount might sit inside a frame that measures around 16x14 inches on the outside. Always measure the artwork itself, not an old frame or mount, when ordering. If you are not sure how to measure properly, our guide on measuring for oversized frames covers the process in detail.

When standard sizes work well

Standard frame sizes in cm and inches are ideal when your artwork happens to match. Photographic prints from labs are almost always a standard size. Certificates and diplomas are typically A4. Posters from reputable print shops usually come in A-series or common imperial dimensions.

The main advantage is cost. Ready-made frames and pre-cut mounts for standard sizes are widely available and significantly cheaper than bespoke alternatives. If you are framing a collection of family photos or a set of matching prints, sticking to standard sizes keeps the budget sensible. For a broader look at what framing costs, see our breakdown of custom framing prices.

When you need bespoke framing

Not everything fits a standard size. Original paintings, hand-cut prints, vintage maps, textiles, and sports memorabilia all tend to come in non-standard dimensions. Forcing an odd-sized piece into the nearest standard frame means either losing part of the image behind the mount or having visible gaps.

Bespoke framing means every element is cut to your exact measurements. The frame, mount, glazing, and backing all match your piece precisely. It also opens up choices you will not find off the shelf: conservation-grade materials, specialist glazing, deeper rebates for canvases, or unusual moulding profiles.

There is a real difference in quality too. We have a dedicated post comparing bespoke framing with high-street alternatives if you want to understand what you get for the investment.

Quick reference: standard frame sizes in cm

For anyone searching for standard frame sizes in cm specifically, here is a combined list of the most commonly framed dimensions in metric. 10 x 15 cm (6x4 photo). 13 x 18 cm (7x5 photo). 15 x 20 cm (8x6 photo). 20 x 25 cm (10x8 photo). 21 x 29.7 cm (A4). 25 x 30 cm (10x12 photo). 29.7 x 42 cm (A3). 30 x 40 cm (12x16). 40 x 50 cm (16x20). 42 x 59.4 cm (A2). 50 x 60 cm (20x24). 50 x 70 cm (common European poster size). 59.4 x 84.1 cm (A1). 61 x 91 cm (24x36). 84.1 x 118.9 cm (A0).

Need a size that is not on the list?

We build every frame from scratch in our workshop in Bollington, Cheshire, so non-standard dimensions are no problem at all. Whether your piece is slightly between sizes or genuinely unusual, we will make a frame that fits it exactly. We have been doing this since 1974 and every frame comes with a 5-year guarantee.

Get in touch with your measurements and we will give you an honest quote. You can also browse our full range of picture framing services to see what we offer.