The right leaflet size depends on how much you need to say, the distribution method and the available budget. These are practical production considerations, not rules.
A5 leaflets
A5 is a versatile format for doorstep distribution and volunteer handouts. It provides enough room for a clear headline, key messages, contact details and a legible imprint.
A4 and DL formats
A4 suits detailed information, while DL can work well for concise messages and letterboxes. Keep essential text away from trim edges and allow space for the required imprint.