Don't size up "for growth" — get the 25-30 liter pack

For most middle schoolers, a 25- to 30-liter backpack is the right size.

That translates to roughly 18-20 inches tall. It’s smaller than most parents think, because the common instinct is to buy big so it “lasts.” That’s backwards. A pack that’s too tall sits below the hips, pulls the shoulders back, and causes the exact back strain you’re trying to avoid.

Fit matters more than capacity. The pack should sit about two inches above the waist, and the width shouldn’t extend past their shoulders. If you’re between sizes, go smaller — a middle schooler carries a few binders and maybe a Chromebook, not a week’s worth of camping gear. A smaller pack also forces them to pack light, and 1/3 of a giant bag weighs less than 1/3 of a medium bag. Weight-wise, loaded should stay under 10-15% of their body weight.

The two things I’d check before buying: torso length (measure from the shoulders to the waistline, not total height) and padded shoulder straps. Everything else — pockets, colors, brand — is their call.

Their back