Sorry, if this is obvious but I'm new to this. How do I find out the iamge size in inches when printed and how do I know the resolution? Are all 300dpi?
I know people will answer you shortly. I'm afraid I can't help you with this. It sounds like you need to print an image. What is it being used for? And how large do you need the image to be?
Maybe this online calculator can help you to calculate, how large a certain image (in pixels) will be printed, when you print it with a 300 dots per inch (dpi) resolution:
You may have to change the language to English, because this is originally a German site.
You can't see the (dpi) resolution of the pictures here in the stock. But I think most of the photos are made with 72dpi. The graphics? I don't really know but a lot graphik programms start with a 72 dpi resolution when you begin to create a picture and you have to change it if you want something else. So I would believe the most graphiks are also made in 72 dpi.
You have the dimensions meter under each image. Then you just calculate.
3000x2000 image in 72 dpi is (3000/72)x(2000/72) - 41,6 inches on 27,7 inches.
3000x2000 image in 300 dpi is 10 inches on 6,66 inches.
You can change the dpi in almost every graphics software.
If you have a printed image (in a magazine) and you do not know it's dpi, you must ask the editor. Different titles use different resolutions, usually between 150 and 600 dpi.