Photo and picture frame sizes describe the picture the frame holds, not the frame itself. An A3 frame takes an A3 print (29.7 × 42 cm), a 10x8 frame takes a 10 × 8 inch photo (25.4 × 20.3 cm), and so on. The most common sizes in the UK are 6x4, 7x5, 10x8, A4 and A3. The frame itself is bigger than its size name, by the width of the moulding on every side.
That's the short answer. The rest of this guide covers the things most size charts skip: which prints actually fit which frames without cropping, how big a frame really looks on the wall, and which mount sizes give you an even border.
In this guide
The UK size chart
In the UK, photo sizes are usually written long side first (10x8, 7x5), while US shops write them the other way round (8x10, 5x7). They're the same size. Paper and posters use A sizes or metric sizes instead.
| Size | Inches | Centimetres | Usually used for |
|---|---|---|---|
| 6x4 | 6 × 4 | 15.2 × 10.2 | Standard photo prints |
| 7x5 | 7 × 5 | 17.8 × 12.7 | Photos, postcards, small prints |
| 8x6 | 8 × 6 | 20.3 × 15.2 | Phone photos |
| 10x8 | 10 × 8 | 25.4 × 20.3 | Portraits, wedding photos |
| 14x11 | 14 × 11 | 35.6 × 27.9 | Art prints |
| 16x12 | 16 × 12 | 40.6 × 30.5 | Prints and larger photos |
| 20x16 | 20 × 16 | 50.8 × 40.6 | Statement photos and prints |
| 24x18 | 24 × 18 | 61 × 45.7 | Posters |
| 36x24 | 36 × 24 | 91.4 × 61 | Large posters |
| A5 | 8.3 × 5.8 | 21 × 14.8 | Cards, small prints |
| A4 | 11.7 × 8.3 | 29.7 × 21 | Art prints, certificates |
| A3 | 16.5 × 11.7 | 42 × 29.7 | Art prints, posters |
| A2 | 23.4 × 16.5 | 59.4 × 42 | Posters, large prints |
| A1 | 33.1 × 23.4 | 84.1 × 59.4 | Large posters |
| A0 | 46.8 × 33.1 | 118.9 × 84.1 | Oversized prints |
| 50 x 70 cm | 27.6 × 19.7 | 70 × 50 | European posters |
| 70 x 100 cm | 39.4 × 27.6 | 100 × 70 | Large posters |
Square frames come in sizes such as 8x8, 12x12 (the one for a vinyl record sleeve) and 20x20 inches.
A sizes, and how they fit together
Each A size is exactly half of the one above it. Fold an A3 sheet in half and you have two A4s; put two A3s side by side and you have an A2. Because every A size has the same shape, a print scales up or down between them without cropping.
So yes, A2 is bigger than A3: twice the area, and the same as two A3 sheets side by side.
50 x 70 cm, A2 and 20 x 28 inches
These three get mixed up more than any others, and plenty of size guides get them wrong. They are three different sizes:
| Size | Centimetres | Compared with A2 |
|---|---|---|
| A2 | 42 × 59.4 | - |
| 20 x 28 inches | 50.8 × 71.1 | About 9 cm wider and 12 cm taller |
| 50 x 70 cm | 50 × 70 | 8 cm wider and 10.6 cm taller |
A 50 x 70 cm poster is noticeably bigger than A2, and slightly smaller than 20 x 28 inches. None of them will fit each other's frames. Posters from Scandinavian and European shops are usually 50 x 70 cm; posters from US shops are often 18 x 24 or 24 x 36 inches.
One useful quirk: 50 x 70 cm is almost exactly the same shape as the A sizes. So an A2 print sits neatly inside a 50 x 70 cm frame with a mount, with a border of about 4 cm at the sides and 5.3 cm at the top and bottom.
Will my photo fit? Matching the shape
Two frames can be similar in size but a different shape, and that's what causes cropping or uneven gaps. Match the shape of your picture to the shape of the frame:
| Your picture | Its shape | Frames with the same shape |
|---|---|---|
| Phone photo (most phones) | 4:3 | 8x6, 16x12, 30 x 40 cm, 60 x 80 cm |
| Camera photo (most cameras) | 3:2 | 6x4, 12x8, 30 x 20 cm |
| A-size art print or poster | About 1:1.41 | A5 to A0, and almost 50 x 70 cm and 70 x 100 cm |
| 10x8 photo | 5:4 | 10x8, 20x16 |
| Square photo or record sleeve | 1:1 | 8x8, 12x12, 20x20 |
For example, a 10x8 photo is close in size to A4 but a different shape, so it would leave gaps in an A4 frame. If your picture doesn't match a frame's shape, a custom-cut mount or a made to measure frame solves it.
Frame sizes with a mount
A mount is the card border between the picture and the frame, so the frame needs to be bigger than the print. Most guides just say "go up a size". The table below shows what that actually looks like, because some pairings give a nicely even border and others leave the top and bottom much deeper than the sides.
| Frame | Border at the sides | Border top and bottom | |
|---|---|---|---|
| 6x4 | 10x8 | 5 cm | 5.1 cm (even) |
| 7x5 | 10x8 | 3.8 cm | 3.8 cm (even) |
| 8x6 | 12x10 | 5.1 cm | 5.1 cm (even) |
| A4 | A3 | 4.4 cm | 6.2 cm |
| A4 | 40 x 50 cm | 9.5 cm | 10.2 cm (nearly even) |
| A3 | A2 | 6.2 cm | 8.7 cm |
| A3 | 50 x 70 cm | 10.2 cm | 14 cm |
| A2 | 50 x 70 cm | 4 cm | 5.3 cm |
| A2 | A1 | 8.7 cm | 12.4 cm |
Borders are for a portrait picture, measured to the edge of the print. The mount window is cut a few millimetres smaller than the print so it holds the edges, so the visible border is very slightly wider. A deeper border at the bottom is a traditional look and many people prefer it; if you want a perfectly even border, our custom-cut mounts can be made to any width.
How big the frame looks on the wall
The size name is only the inside. To get the outside, add the moulding width twice to each measurement. Here's how much difference the moulding makes:
| Frame | Slim 20 mm moulding | Medium 35 mm moulding | Wide 50 mm moulding |
|---|---|---|---|
| A4 | 25 × 33.7 cm | 28 × 36.7 cm | 31 × 39.7 cm |
| A3 | 33.7 × 46 cm | 36.7 × 49 cm | 39.7 × 52 cm |
| A2 | 46 × 63.4 cm | 49 × 66.4 cm | 52 × 69.4 cm |
| 50 x 70 cm | 54 × 74 cm | 57 × 77 cm | 60 × 80 cm |
You don't need to work it out yourself on our frames. Each frame page shows the external size for whichever size you pick, and a room view shows the frame hanging on a wall at the right scale, which is a lot easier to judge than a set of numbers.
As a rough guide for choosing a size, a single picture above a sofa or sideboard usually looks best at around half to two-thirds of the furniture's width. Cut a piece of paper to the outside size and tape it to the wall before you order.
Measuring your print
- Measure the width and height from edge to edge, ideally in millimetres.
- If the print has a white border you want to keep, include it. If you'd rather hide it, measure just the image and use a mount to cover the border.
- Pick the frame size that matches. The lip of the frame covers a few millimetres round the edge, which is what holds the picture in place.
- If it doesn't match any standard size, a made to measure frame will fit it exactly (UK delivery only).
Still torn between two frames? Upload a photo of your print using the Preview Your Own Artwork button on any of our frame pages. You'll see it in the frame at the right size, and you can flick between finishes before you decide. The photo stays on your device.
Key takeaways
- A frame's size is the size of the picture it holds. An A3 frame fits a 29.7 × 42 cm print.
- The most common UK sizes are 6x4, 7x5, 10x8, A4 and A3. 10x8 and 8x10 are the same size.
- 50 x 70 cm is bigger than A2 and smaller than 20 x 28 inches. They don't fit each other's frames.
- Match the shape as well as the size: phone photos suit 8x6 or 16x12, A-size prints suit A frames.
- 7x5 in a 10x8 frame and 8x6 in a 12x10 frame give an even mount border all round.
Common questions
What are the standard photo frame sizes in the UK?
The most common are 6x4, 7x5, 8x6 and 10x8 inches for photos, and A4, A3 and A2 for prints and posters. 50 x 70 cm is also common for posters.
Is A2 bigger than A3?
Yes. A2 (42 × 59.4 cm) is twice the size of A3 (29.7 × 42 cm).
What size is an A3 frame?
It holds an A3 print, which is 297 × 420 mm, or about 11.7 × 16.5 inches. The outside of the frame is bigger by the moulding width on every side.
What size is an A4 frame?
It holds an A4 print: 210 × 297 mm, or about 8.3 × 11.7 inches.
What size frame do I need for an A4 print with a mount?
An A3 frame is the usual choice, with a border of about 4.4 cm at the sides and 6.2 cm at the top and bottom. For a more even, generous border, a 40 x 50 cm frame gives about 10 cm all round.
Is 10x8 the same as 8x10?
Yes. UK shops tend to write the long side first (10x8), US shops the short side (8x10). Both are 25.4 × 20.3 cm.
Is 50 x 70 cm the same as A2?
No. 50 x 70 cm is bigger than A2 (42 × 59.4 cm), so an A2 print will be loose in a 50 x 70 cm frame unless you add a mount.
Is the frame size the inside or the outside?
The inside. The size tells you what picture fits. How big it is on the outside depends on the moulding width.
Can I see my print in the frame before ordering?
Yes. Use Preview Your Own Artwork on any of our frame pages, upload a photo of your print, and it'll appear in the frame at the right size.
More framing guides: how to hang a picture and how to frame a canvas painting.
See all our picture frames. Every one is handmade to order by Guild Certified Framers, in A, inch and metric sizes.
About the author: Trevor Beers
Trevor Beers is a guest writer for East Side Studio London. With two degrees in English language and a passion for contemporary art, he explores the intersections of culture, criticism, and collecting. Splitting his time between London and Austin, Trevor brings an academic eye to emerging art scenes, offering thoughtful perspectives on today's evolving art landscape.
