Be aware that this is a VERY general guide and may not apply to all cases. How many pages of text do you have? Assuming that you want to include pictures, tables, etc., in your poster, the table below offers a general idea of what size poster you may be able to create without having to make the text too small or too big. For example, will your poster be mostly text or a combination of text, graphs, charts, tables, and photos? Most likely, your presentation will be a mix of all of the above. To determine what size is best for your poster presentation, you should look at the amount of information you want to present. Meetings outside the US often provide smaller spaces and ask for vertical scientific posters (tall and narrow) in metric measurements. It is common for conferences in the United States to provide a 4x8 foot space (48x96 inches) to the attendees, but not always, so be cautious. You would need to follow their instructions, or you may have a poster that is too big or too small for the provided space. As a reference, it is a a little smaller than the better-known standard US letter size, which is the typical paper size most basic home-printer uses and is 8.5x11in.
Each conference publishes poster session guidelines indicating the space they are making available for poster presentations. The 11x17 poster means that the poster is made by 11×17 paper, or other kind of flat surface materials of same dimensions. Before you download a template or create a research poster from scratch, you'll have to know what size poster you need. Because of its small size, the poster can fit bulletin or shared community boards, and is more suitable for indoor use, it is very popular in small exhibition halls or corridors as a publicity medium.