PowerPoint add-in PPT Productivity lets you set a specific vertical gap or space between objects in PowerPoint.

This feature lets you quickly specify the vertical gap between one or more selected shapes or objects on your PowerPoint slide. For example set the vertical gap between selected shapes to be 2pts or 20pts (enter whatever number you prefer). Perfect for making your spacing exact and consistent.

The Set Vertical Gaps feature is in the Gaps feature group on the Format Toolbar.