When it comes to displaying your favourite memories or art, choosing the right-sized photo frame is just as important as selecting the piece that is being framed. Whether you’re framing a family portrait, a piece of artwork, or a moment captured during a special occasion, the size of the frame can greatly impact the overall look and feel of your display. Deciding on the correct size frame can be confusing, especially if you are dealing with uncommon print sizes and measurement conversions, therefore in order to ensure you get the best fit for your most cherished images, we’ve put together a helpful sizing guide below.
Keep reading as we walk you through standard frame sizes, provide handy conversions from inches to centimetres, and offer tips to help you showcase your photos beautifully and accurately in any space.
Standard Paper and Poster-Sized Frame Conversions
Whether you’re building a gallery wall with mixed print sizes or looking to frame your favourite poster, finding a frame that fits can be difficult if you’re unfamiliar with the conversions. The most typical poster size frames tend to be A1 (extra-large), A2 (large), A3 (medium) and A4 (small). If you’re unsure what size frame will be best for your print, we have created a size conversion chart below that details the exact measurements in centimetres for the various ‘A’ paper sizes.
| Exact Paper Size | Similar Photo Size | |
| A5 | 14.8 x 21 cm | 15 x 21 cm |
| A4 | 21 x 29.7 cm | 21 x 30 cm |
| A3 | 29.7 x 42 cm | 30 x 40 cm |
| A2 | 42 x 59.4 cm | 40 x 60 cm |
| A1 | 59.4 x 84.1 cm | 60 x 80 cm |
Keep in mind that the frame you choose for your poster will generally be one to two inches wider than the poster itself, depending on the material of the frame you opt for and the thickness of the border. In order to get the correct aspect ratio we recommend measuring directly down the centre of the image vertically and then across the image at the top to determine which size frame will be best suited.
Rectangular Photo Frame Size Conversions
Most photographs will typically fit into a rectangular-shaped photo frame. The most common sizes are measured in inches - 4×6″, 5×7″, 8×10″ and 16×20″. Depending on whether or not you want to border your image with a photo mount (or mat as they are also referred to), the size of the frame you will need will vary. Below we have listed the conversions for the typical size of rectangular photographs in inches and the exact measurements they convert to in centimetres.
| Inches | Exact Photo Size (cm) | Similar Photo Size |
| 2.5 x 3.5 | 6.4 x 8.8 cm | 6 x 9 cm |
| 6 x 4 | 10.2 x 15.2 cm | 10 x 15 cm |
| 7 x 5 | 12.6 x 17.7 cm | 13 x 18 cm |
| 8 x 6 | 15.2 x 20.3 cm | 15 x 20 cm |
| 8 x 10 | 20.3 x 25.3 cm | 20 x 25 cm |
| 8 x 12 | 20.3 x 30.3 cm | 20 x 30 cm |
| 10 x 12 | 25.3 x 30.3 cm | 25 x 30 cm |
| 11 x 14 | 27.8 x 35.2 cm | 28 x 35 cm |
| 12 x 16 | 30.3 x 40.5 cm | 30 x 40 cm |
| 12 x 18 | 30.3 x 45.7 cm | 30 x 46 cm |
| 16 x 20 | 40.5 x 50.6 cm | 40 x 50 cm |
| 16 x 22 | 40.5 x 55.9 cm | 40 x 60 cm |
| 16 x 24 | 40.5 x 60.9 cm | 40 x 61 cm |
| 20 x 24 | 50.5 x 60.9 cm | 50 x 61 cm |
| 20 x 28 | 50.5 x 71.1 cm | 50 x 70 cm |
| 20 x 30 | 50.5 x 76.2 cm | 50 x 76 cm |
| 24 x 36 | 60.9 x 91.4 cm | 61 x 91 cm |
Keep in mind that if you wish to use a photo mount to add more dimension to your framed image and create a slight border, you will need to add an extra couple of millimetres to each side of your image to get the correct measurements for your chosen frame. The size of the mount you choose will depend on the visual effect you want. For example, if you wish to have a ‘frame within a frame’ look, you will need to choose a wider mount border, or if you want to make the photo look more prominent, then you should opt for a mount that is only a couple of millimetres wider than the image.
Square Photo Frame Size Conversions
All square images have a 1:1 ratio, with each side of the image being equal. Below we have converted the typical 1:1 inch measurements of square images into the exact size in centimetres so that you can pick a photo frame that will accurately fit your image. We recommend choosing a frame that is slightly larger than the dimensions of the photo to allow room for the rebate.
| Inches | Exact Photo Size (cm) | Similar Photo Size |
| 3 x 3 | 7.6 x 7.6 cm | 8 x 8 cm |
| 4 x 4 | 10.2 x 10.2 cm | 10 x 10 cm |
| 5 x 5 | 12.6 x 12.6 cm | 13 x 13 cm |
| 6 x 6 | 15.2 x 15.2 cm | 15 x 15 cm |
| 7 x 7 | 17.7 x 17.7 cm | 17 x 17 cm |
| 8 x 8 | 20.3 x 20.3 cm | 20 x 20 cm |
| 10 x 10 | 25.3 x 25.3 cm | 25 x 25 cm |
| 12 x 12 | 30.3 x 30.3 cm | 30 x 30 cm |
| 14 x 14 | 35.2 x 35.2 cm | 35 x 35 cm |
| 16 x 16 | 40.5 x 40.5 cm | 40 x 40 cm |
| 20 x 20 | 50.6 x 50.6 cm | 50 x 50 cm |
| 24 x 24 | 60.9 x 60.9 cm | 61 x 61 cm |
Again, similar to the rectangular photo frames mentioned above, you can choose to mount your image which will require you to add extra millimetres to your measurements when picking out your square photo frame. Our collection of photo frames comes in a wide range of sizes and materials to suit your framing preferences. From modern, slim silver-plated frames to traditional, wooden photo frames for a timeless aesthetic, no matter what size image you have, we’ve got a quality picture frame option to fit.
Keep in mind that no matter what style frame you are using, it's important to take into account the rebate when sizing up your image. A rebate is the part of the frame that covers the edges of the image, so the total viewing area at the front of the frame will be smaller than the frame size. Most rebates will overlap the edge of pictures by about 5mm on either side, reducing the total viewing area of your image. With this in mind, it is important to remember that the frame will always cover a small part of your image to ensure you have a clean edge-to-edge image with no white gaps.
Pick the right frame for you at Kenro
Head on over to our full range of photo frames to discover options made for every moment. Whether you’re looking to showcase photos around your home from your wedding day or family holiday, or you’re searching for a variety of frames to create a unique gallery wall to display your art, you’ll find it here at Kenro.
