This was one of my first questions when I first started because I really didn’t know where to begin!
A good start is to check out the standard frames that are offered in local stores and online; Another way you could decide on best sizes is by checking out your competition and look at the sizes that they offer.

Love this graphic above? I sell this in my digital etsy store – it is perfect on listings to show customers how print sizes compare; Check it out here : https://www.etsy.com/uk/listing/555112656/wall-art-size-guide-print-size?ref=shop_home_active_21
This is what I settled on for the majority of my prints :
- 5×7 inches
- 8×10 inches
- 11×14 inches
- 16×20 inches
The above is how I started and works pretty well – especially in the American market as these are the sizes of prints that most people are used to.
Around 18 months in I realised that I was completely missing a trick because, being located in the UK, I noticed that local stores also sold the standard international paper sized frames. So I now also offer
- A5
- A4
- A3
and these are also very popular because most people buy ‘off the shelf’ frames.
You can find the facebook page here :
How To Sell Prints Online Facebook Page
And here is the facebook group :
How To Sell Prints Online Facebook Group