How Much Kids' Clothing Goes Unworn Before It's Outgrown?

Children's clothing has one of the shortest useful lives of any consumer product. Kids grow fast, sizing is inconsistent, and seasonal buying habits mean wardrobes fill up faster than small bodies can wear things out.

The result: enormous amounts of clothing that go unworn — or barely worn — before they're outgrown and moved on.

This research compiles data from resale market reports, parenting surveys, apparel utilization studies, and pediatric growth guidance to quantify just how much children's clothing goes unused, and why.

Key Highlights

• 31.4% of kids' and baby items owned by U.S. households are unused or no longer used — representing an estimated 272.6 million items worth $13 billion sitting idle in homes

• An estimated 100 million kids' and baby items worth $4.5 billion were thrown away in 2021

• 30% of clothing items in wardrobes have not been worn for at least a year, often because they no longer fit

• Only 20% of parents report their child fit garments exactly as labeled, suggesting sizing mismatch is a major driver of underuse

• Babies can outgrow newborn clothing sizes within days; clothing labeled for three months may only fit during the first few weeks of life

• 75% of parents donated or gave away at least one kids' or baby item in the past year; 50% sold at least one item secondhand

• U.S. families planned to spend an average of $249.36 on clothing and accessories and $169.13 on shoes per child for the 2025 back-to-school season

• The secondhand kids' and baby market is projected to reach $12.8 billion by 2030

A Third of Kids' Clothes Sit Idle in U.S. Homes

According to Mercari's Family Reuse Report, U.S. households collectively own 868.1 million kids' and baby items worth $39.6 billion. Of those, 31.4% are classified as unused or no longer used — amounting to 272.6 million items worth an estimated $13 billion gathering dust in closets and drawers.

The same report estimates that 100 million kids' and baby items worth $4.5 billion were discarded in 2021 alone, with 26.9% of parents reporting they had thrown away kids' or baby items in the past year.

That figure sits alongside a broader pattern in clothing consumption: WRAP research found that roughly 30% of items across all wardrobes go unworn for at least a year.

In adult wardrobes, the culprits are often impulse purchases or occasion-specific pieces. In children's wardrobes, the dynamic is more structural — clothes are outgrown before they can be worn out, regardless of how practical or well-intentioned the original purchase was.

Rapid Growth Creates Extremely Short Usage Windows

One of the most significant drivers of clothing underuse in early childhood is simply how fast babies and toddlers grow.

Guidance from the American Academy of Pediatrics notes that many babies outgrow newborn clothing sizes within days, and even clothing labeled for three months may only fit during the first few weeks of life.

Because infants grow so rapidly in their first year, parents often purchase clothing across multiple size ranges or buy ahead of anticipated growth stages — meaning many garments are worn only a handful of times, or not at all, before a child moves on to the next size.

The challenge intensifies when gifts are factored in. Newborn and infant clothing is among the most commonly gifted categories for new parents, and well-meaning gifts in a single size can arrive in quantities that far exceed what a baby will actually wear before outgrowing them.

A newborn who receives six onesies in the same size may realistically wear each of them once or twice before they no longer fit.

Broader clothing utilization research supports this pattern: approximately 30% of clothing items across wardrobes have not been worn for at least a year, with poor fit cited as a primary reason.

Sizing Inconsistency Compounds the Problem

The issue isn't just growth — it's that children's clothing sizing is notoriously unreliable, making it difficult for parents to purchase confidently.

Mintel research found that 29% of U.S. parents report inconsistency in children's clothing sizing, and 31% say they make their children try clothes on before purchasing to ensure fit.

A study on size-adaptive garments for toddlers found that only 30% of parents purchased clothing matching the exact size or age label, and only 20% of parents reported their child fit garments exactly as labeled.

This mismatch means parents frequently buy items that end up being too large, too small, or simply unusable by the time sizing circumstances align — leaving garments worn rarely or never.

Unlike adult clothing, where an ill-fitting item might eventually be worn anyway or altered, children's clothing has a hard expiry date. A shirt bought too large in anticipation of growth may finally fit at the same moment the season changes or the child's preferences shift — and by then it may never get worn at all.

Seasonal and Event-Driven Buying Adds to Accumulation

Children's clothing purchases tend to cluster around seasonal shopping moments, which can accelerate accumulation beyond what children can realistically wear.

According to the National Retail Federation, families with K-12 students planned to spend an average of $249.36 on clothing and accessories and $169.13 on shoes per child during the 2025 back-to-school shopping season.

Deloitte's 2025 Back-to-School Survey found that 62% of parents say their children influence them to spend more on back-to-school purchases, while 57% say they can be persuaded to buy a special first-day-of-school outfit — a category of garment particularly prone to limited use.

This kind of event-driven purchasing creates a recurring cycle: large quantities of clothing are bought in concentrated windows, some items get heavy rotation, and others — bought in the wrong size, for an occasion that didn't materialize, or simply in excess of what a child needs — never get worn at all.

When the next seasonal shopping moment arrives, the cycle repeats.

Secondhand Markets Are Absorbing the Overflow

Despite the scale of waste, secondhand markets are playing a meaningful role in extending the life of children's clothing.

Mercari's research found that 62% of parents purchased secondhand kids' or baby items within the past year. Morning Consult similarly found that 59% of parents rely on secondhand products to meet family needs.

On the supply side, 75% of parents donated or gave away at least one kids' or baby item in the past year, and 50% sold at least one item secondhand — reflecting a broad cultural norm around passing children's clothing on rather than disposing of it.

The relative ease of reselling children's clothing — which often shows minimal wear precisely because it was outgrown so quickly — has helped fuel a robust and growing resale category.

The Mercari report projects the market for secondhand kids' and baby items could reach $12.8 billion by 2030, driven by growing adoption of resale and reuse for children's products.

Methodology

This analysis compiles publicly available statistics from resale market reports, parenting surveys, apparel utilization studies, and pediatric growth guidance. Data sources include WRAP clothing utilization research, Mercari's Family Reuse Report (produced with GlobalData), Morning Consult consumer surveys on secondhand purchasing, American Academy of Pediatrics guidance on infant growth and clothing sizing, Mintel research on children's apparel fit, National Retail Federation retail spending surveys, and Deloitte consumer behavior research on back-to-school shopping.