Your lunch bag won't fit. A bento box will.

Most lunch boxes are too tall, but slim bento boxes slide right in.

Here’s why: a standard mini fridge’s freezer eats a good four inches off the top, so the usable shelf height is only about eight to ten inches. A normal soft-sided lunch bag is ten to twelve inches tall, which means it jams against the freezer or has to be laid on its side, causing your yogurt to explode. Again.

What fits are flat, rectangular bento boxes—like a Monbento, Yumbox, or even a basic stackable container without the dome. They’re only two or three inches tall, so they slide under the freezer and leave room for a drink.

“Perfectly” still depends on your exact fridge, since mini fridges aren’t built to a universal spec. Measure your shelf height before buying. When in doubt, go wide and short instead of tall and skinny.

You’re not gaining anything by cramming a lunch bag into a tiny fridge, so buy the thing that actually fits.