Cups and mugs take up prime cabinet shelf space but use almost none of it — a stack of mugs is mostly air, yet it sits on the shelf you need for plates. The space directly under that shelf is empty, which is the cheapest storage you own. An under-cabinet rack drops a shelf into that dead gap and gets the mugs off the surface you actually cook around.
Why under the shelf, not in it
The few inches below a cabinet shelf are usually wasted — too short to stand a plate, too shallow to use. A expandable under-cabinet rack ($27) fills exactly that strip with a second shelf sized for mugs, small bowls, and spice jars. You keep the shelf above for the flatware and free the cabinet floor for the bulky stuff.
No drill means reversible
Drilling into a cabinet box is permanent and landlord-hostile. This rack mounts with no holes, so it comes down clean if you rearrange or move. That also makes it a five-minute job instead of an afternoon with a level, and there's nothing to patch if you change your mind next month.
Expand to fit the opening
Cabinets vary in width, so the rack expands to meet your opening instead of forcing you to buy a fixed size that leaves a gap. Measure the inside width, set the rack to match, and the mugs line up instead of hanging off the edge. A snug fit is what keeps it from wobbling when you pull a cup.
Pair it with a hanging tier
If you also have air under an upper shelf elsewhere, a hanging shelf organizer ($25) does the same trick in a different spot — under a cabinet, over a counter. The two together clear most of a small kitchen's mug-and-spice clutter without touching a wall.
Get the mugs off the shelf: shop the under-cabinet rack or see the Cabinet set.
Mugs aren't the only thing that strip under a shelf can hold. This roundup of under-cabinet storage runs through every no-drill mount — rack, clip-on basket, hanging tier — and the width each one needs.