Most adults want a 1.5 to 2 liter lunch box

Most adults should look for a 1.5 to 2 liter lunch box (about 6 to 8 cups), unless you’re packing one small meal.

That sounds vague, but it’s not. A standard main dish — pasta, a rice bowl, a sandwich with fruit — runs 2 to 3 cups. Add a side or a snack and you’re at 4 to 6 cups. That’s your 1.5L box. If you like multiple sides or a hearty salad, step up to the 2L.

Salads are the wildcard. Leafy greens fluff up to twice their actual weight, so a “small” salad can eat a full liter on its own. If salads are a weekly thing, size up.

For kids, halve it: 0.6 to 1L is plenty. And don’t overthink the math — if your regular meal fits with a half-inch of air at the top, that’s the right size. The only real mistake is buying too small and fighting the lid shut.

Future You deserves a lid that closes without a wrestling match.