Clothes that fit your littles,
and your conscience.
Never panic over another too-small outfit again. We’ve got the Next Size Up covered.
How it Works
Step 1:
Tell us your Child’s Size
Or enter their measurements in our Perfect Fit Calculator to make it even easier.
No need to guess, we know kids grow fast, and sizes aren’t one-size-fits-all.
Step 2:
We Build your Bundle
Each item is parent-approved, and hand-selected with care.
Cleaned, curated and packaged with love — just like we’d do for our own kids.
Step 3:
Clothes that Feel Good
No fast-fashion guilt, overfilled laundry baskets, or last-minute scrambling.
Just clothing that keeps up with your little, budget, and values.
Why We’re Here
Millions of children’s clothes end up in landfills every year, while many families struggle to afford what they need.
Parents are often forced to choose between what’s sustainable and what’s actually affordable.
At Next Size Up, you don’t have to pick.
clothing items have entered U.S. landfills since May 1, 2025.
clothing items saved from landfills by Next Size Up — and counting.
Prepare for the season ahead with a handpicked set of 25+ secondhand kids’ clothes. Affordable, eco-friendly, and perfect for keeping your child dressed sustainably all season long.
Shop Our Bundles
Explore affordable, sustainable baby and toddler clothing bundles (NB–5T) designed for every stage and season. From monthly secondhand kids’ clothing subscriptions to seasonal sets and full wardrobe bundles, our curated collections help families shop eco-friendly, gently used clothes online with confidence and ease.
Get a curated 10+ item bundle of gently used baby or toddler clothes (NB–5T) delivered each month. Sustainable, affordable, secondhand baby clothing - parenting made simpler.
Build your child’s entire wardrobe (40+ items!) in one go with a complete set of pre-loved, eco-friendly clothing. Budget-friendly, sustainable, and curated to cover all the essentials.
How to Make an Impact
Whether you're passing along outgrown baby/toddler clothes (Newborn–5T) or sponsoring a bundle for a family in need, your contribution helps reduce waste and lighten the load for another parent.
Choose the way that works best for you — every action makes a difference.
DIY - Print Label
Fill out the attached form to submit a request a prepaid shipping label. We will email the label directly to your preferred email address, so you can easily print and ship the clothes you’re ready to pass on.
Request a Donation Kit
Fill out the attached form to request a donation kit. We’ll send you an eco-friendly return bag with a prepaid label, ready to fill and drop at USPS, as well as our endless gratitude.
Porch Pickup - MA & RI
Fill out the attached form to let us know you have local clothes to donate! We’ll schedule a time that works for you, and pick up your clean, preloved kids’ clothes right from your doorstep.
Sponsor a Family
Help cover the cost of a clothing bundle for a family facing financial hardship. Your support keeps kids comfortably dressed — and gives parents one less thing to worry about.
Testimonials
At Next Size Up, we're parents, too — juggling messy meals, sudden growth spurts, and never-ending laundry. This business was born out of a real need: making clothing for fast-growing little ones more practical, more affordable and less wasteful.
Hi, I’m Mae — mom of 2 amazing kids, and founder of Next Size Up. I created this company to make shopping for children’s clothes more simple, sustainable, and affordable for every family.
We collect gently used baby and toddler clothes (Newborn-5T), sort and curate them into stylish, size-specific bundles, and deliver them to your door - making it easier to keep up with growth spurts without overspending or over-consuming.
But Next Size Up more than just a shop.
Every bag of clothes passed on helps extend the life of quality clothes, reduce textile waste, and support another growing family. Every bundle you purchase shifts us toward something better - sustainability, affordability, and shared community impact.
Together, we’re proving that small actions - one bag of outgrown clothes, one thoughtfully chosen bundle - can add up to real change.
At Next Size Up, we believe sustainability and affordability should go hand in hand - because every growth spurt is a chance to do better, together. 🌱
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