I have not biggest size! I shot in 12.5 megapixels so the original size is 4287 x 2847, it's impossible enlarge because the image lose quality. But professional print service (deviantart or other..) know how to print at biggest size using an 4287 x 2847 in 300dpi. In DA prints I see Photo format lustre 51x76, Canvas 61x91 or Art Print 61x91. If you want to print by youself you can buy at 2.99 on 500px.com the HD wallpaper.. but the biggest size is 4287 x 2847 .. there's not biggest size, sorry.