How Do You Know What Clothing Size to Buy for a Child?

A guide to choose right size to ensure comfort, freedom of movement and longer wear.

Buying children’s clothing can be tricky — especially online or when you’re choosing a gift. Sizes vary between brands, babies and kids grow at different rates, and the labels can be confusing.

Picking the right size is essential to ensure comfort, freedom of movement, and longer wear. That's why at Cozmo we created this guide.

We hope that with this step-by-step guide you’ll better understand kids’ clothing size charts and enjoy a smoother shopping experience.

1. Check the Brand’s Size Chart

Baby and kids’ size charts for clothes can be confusing because every brand uses different measurements.

However, in general, sizes correspond to the child's age. For instance, a size labeled "3M" usually fits babies up to 3 months old, rather than starting from 3 months.

This is actually a common misconception among first-time parents when they start shopping online.

Usually choosing the right size for newborn clothes, it can be even more challenging. That's why at Cozmo we include both the size and the baby’s length in centimeters as a guide in our newborn collection.

For toddlers, the sizing can also be tricky. Why? Because some clothes come in both 24M and 2Y. The key difference here is that “24 months” is for babies still in diapers, while “2Y” is meant for toddlers who are already potty-trained and require less room in the seat.

These guidelines are general. But the best way to get the right fit is to measure your child’s height, chest, waist, and inside length (for pants, jumpsuits, overalls, etc.), and compare with the brand’s size chart.

At Cozmo, we try to make this even easier by displaying the model child’s measurements in the “Size & Fit” section of each product, so you can choose with confidence.

Cozmo Size Chart

2. Consider the Child’s Age and Growth Spurts

Children grow quickly, so it’s always recommended to leave a little room when choosing a size.

Still, keep in mind that the approach varies by age. For babies, you’ll typically need a new size every 3 months or so due to their rapid growth. For older children, however, the same garment can last for more than a year.

Also, many of Cozmo's products are designed to be adjustable. For instance, our baby and kids' pants typically feature an interior elastic with buttonholes, allowing the waistband to be easily adapted. This means the pants can last through several stages of growth.

3. Pay Attention to Fabric and Fit

The type of fabric used in a garment can significantly influence its fit. Knit and tricot fabrics are more flexible and easily accommodate movement, while structured cotton or woven materials offer a polished appearance but provide less stretch. Fitted garments tend to feel snug, whereas relaxed silhouettes allow for more room.

Additionally, it's important to follow the care and cleaning instructions on the label to avoid shrinking or distorting the fabric, as this can alter the fit after washing.

4. Use Reviews and Fit Details to Your Advantage

Even though we always strive to follow our children's clothing size chart, slight variations can occur between different garments or styles.

That’s why it’s essential to check the product description. At Cozmo, we typically indicate whether a piece has a more fitted or relaxed cut.

Customer reviews can also be very helpful, as other parents often share insights about whether an item runs larger or smaller than expected, or how it holds up after washing. This can be a useful tool for your decision-making.

Additionally, remember that our “Size & Fit” section displays the model child's measurements, providing you with a real-life reference to help you choose the most accurate size for your own child.

5. Think About the Season

Seasonality is important to consider when making clothing purchases.

If you're buying for colder months and plan to layer underneath, you might want to choose a slightly larger size. This approach applies to items like sweatshirts, sweaters, jackets, and coats.

For summer clothing, however, a lighter and more fitted style may be preferable.

By thinking ahead about how and when you'll wear each piece, you'll be able to make more informed choices.

6. When in Doubt, Size Up

If you're uncertain about sizing, it's best to opt for the larger size. A garment that is slightly loose is more comfortable than one that is too tight, and it will last longer as your child grows.

As mentioned earlier, many of our bottoms, such as pants and skirts, feature adjustable waists. Additionally, hems can often be rolled up, providing extra flexibility and extending the garment's lifespan.

Final Tips for a Perfect Fit

Choosing the right size for children’s clothing comes down to a mix of measurement, observation, and planning ahead. Check the size chart, consider growth spurts, and think about how and when the clothing will be worn. Quality pieces like those at CozmoBrand are designed to last and adjust, so your child can enjoy them longer.

And if you still get it wrong, don’t worry — at Cozmo it’s easy to exchange or return an item. See our refund and exchange policy here.