Built by Parents, for Parents

Cassullo Diapers was born from a simple frustration every parent knows — the never-ending cycle of running to the store for diapers. We believed there had to be a better way. Premium quality, delivered on your schedule, at a price that respects your budget.

What We Stand For

Every decision we make comes back to one question: does this make life easier for parents?

Premium Without the Premium Price

We cut out the middleman and deliver directly to you. That means better materials, better fit, and savings you can actually feel — especially with a subscription.

Convenience That Actually Works

Our subscription adapts to your baby. We track their growth, recommend size changes, and ship on a schedule that fits your life. Skip, pause, or cancel anytime.

Community First

Our Diaper Fund lets friends and family contribute to what new parents actually need. No more piles of boxes at the baby shower — just months of comfort delivered to their door.

Safe for Every Baby

Dermatologist tested, hypoallergenic, and free from harsh chemicals. We obsess over materials so you can focus on what matters — your little one.

Diaper Size Guide

Not sure what size your baby needs? Use weight as the primary guide — age ranges are approximate since every baby grows differently.

Newborn~11/day

Up to 10 lbs

0–1 month

Size 1~9/day

8–14 lbs

0–4 months

Size 2~8/day

12–18 lbs

3–8 months

Size 3~7/day

16–28 lbs

5–24 months

Size 4~6/day

22–37 lbs

18–36 months

Size 5~5/day

27+ lbs

3+ years

Size 6~4/day

35+ lbs

4+ years

Tip: If your baby is near the top of a size range, it may be time to size up. Our subscription auto-recommends size changes based on your child's profile.

Frequently Asked Questions