What trim size should a KDP journal or planner be?
Updated 22 September 2026
The common choices are 6 by 9 inches for a journal and 8.5 by 11 inches for a planner, but KDP supports many trims. Pick the size your niche expects, then keep it fixed so the margins, gutter and cover are all sized to it.
The trim size is the finished page size, and it sets everything else: the gutter margin the binding needs, the spine width the cover is built to, and how much room a ruling or a planner grid has. Notebooks and lined journals sit well at 6 by 9; planners and logbooks usually want the room of 8.5 by 11.
In Publisher Studio the trim is chosen once and the page is laid out to it, then the same project exports at that trim to Amazon KDP, Gelato or Kindle. Changing your mind later means the margins and cover resize with it, so decide the size before you build a series around it.