How big (in cm) is the facebook timeline cover?

[Mynameis Bob]

My friend made me a cover photo for my page, however when I tried to upload it it said it was too small. I went on photoshop to resize it, but I'm not sure how big it should be. I could only find the size in pixels through google.

[Viswas]

The timeline cover photo is approximately
10.8 x 4 cm in size.

[Mikai]

it entirely depends on the screen (pixels, zoom level, etc)

[Patters]

It cannot be measured in cm, because it is specified in pixels. The physical size of pixels varies, so 1 cm does not equal a fixed number of pixels.

Images can be sized using real-world physical measurements like centimetres, but that is irrespective of the number of pixels. The size in physical units is just an instruction which tells the computer how big to print the image out, or tells it what size to display it in any software that displays accurate physical sizes. Although websites can specify sizes in physical units, most do not bother.

In Photoshop, there is a checkbox labelled "Resample image" in the Image Size dialog. If this is not checked, the number of pixels in the image can not and will not be changed. Only the physical size can be altered. To change the number of pixels, you need to check this box. This will allow you to edit the number of pixels.

Prior to entering the pixel size, you often need to make sure your image has been cropped to the correct shape, otherwise you will end up squashing it out of shape. So, for example, if you have a square image 5000 x 5000 pixels, and you want to fit it into a box that's 600 x 200 pixels, you need to crop the top and/or bottom of the image away to give it a 6:2 aspect ratio, before shrinking the pixel dimensions, otherwise the image will end up squashed flat from the top and bottom.

You can crop the photo on Facebook itself though, once it is small enough to upload, which may be easier. Set the pixel dimensions to stay locked in proportion (with the little unbroken-chain icon), then enter only the required width. The height will shrink automatically, but it will stay in proportion, and then you can cut the excess off on Facebook.

Edit: I'm sorry; I misread; I thought you said Facebook told you the image was too big. Since it's actually too small, then really you should be looking to find a different image, as making the existing one larger will not look good (Facebook could easily have made it bigger for you, but they don't because it will look bad).

[B K]

Images on websites are measured in pixels, not centimetres. The image in my timeline is 851px × 314px.

Although facebook will rescale and crop an image for you, if it has really small pixel dimensions you may find there is a limit.

If you try to rescale a low resolution image (one with low pixel dimensions) in Photoshop you may find the quality becomes worse - it will simply make it look blurry. You really need to start with a higher resolution image to get good quality.