Baby Clothing Size by Age vs Height: How to Choose the Right Fit Every Time
Deel
One of the most confusing parts of buying baby clothes is sizing labels. Parents often ask: Should I choose baby clothing size by age or by height? The truth is, age labels alone are rarely accurate — and relying on them often leads to clothes that fit too tight or don't last long.
This guide explains how baby clothing sizing really works, how to choose the right fit, and why selecting a slightly bigger size is usually the best decision.
Quick Answer: Should I Choose Baby Clothes by Age?
No — baby clothing sizes should be chosen by fit, not age.
Age labels are only estimates. Babies grow at different speeds, and two babies of the same age can have very different body sizes.
The safest approach is to:
- Use height and weight as a reference
- Prioritize comfort and movement
- Choose the next size up when unsure
Why Age-Based Baby Sizes Are Misleading
Baby clothing sizes like "3–6 months" or "6–9 months" assume average growth — but real babies don't grow on a schedule.
Age-based sizing often fails because:
- Babies have different body proportions
- Growth spurts happen unexpectedly
- Some babies are taller, others are fuller
- Seasonal clothing may need to last longer
This is why parents often find brand-new clothes becoming too small far too quickly.
Height & Weight Matter More Than Age
Height and weight provide a much better indicator of how baby clothes will fit.
When choosing a size:
- Look at the brand's size chart
- Focus on height first, then weight
- Choose the size that allows room rather than tightness
If your baby is between sizes, always size up.
Why Choosing the Bigger Size Is the Safer Choice
Many parents worry that bigger clothes will be uncomfortable or look oversized. In reality, babies benefit from extra space.
Benefits of sizing up:
- Allows free movement of arms and legs
- Prevents tight pressure on the belly and chest
- Makes dressing and diaper changes easier
- Adapts as your baby grows
Within weeks, a slightly larger size often becomes the perfect fit.
Sizing for Comfort, Sleep & Movement
Babies spend much of their day moving, playing, and sleeping. Tight clothing can:
- Restrict movement
- Cause discomfort during naps
- Leave marks on sensitive skin
A looser, comfortable fit supports better sleep and happier movement throughout the day.
Seasonal Clothing: Why Bigger Sizes Work Better
Seasonal baby clothing — especially winter outfits — benefits even more from choosing a larger size.
A bigger size:
- Allows space for light layering
- Feels more comfortable in thicker fabrics
- Lasts through the entire season
Tight seasonal clothing often becomes unusable before the season ends.
How Lunakit Baby Approaches Sizing
At Lunakit Baby, clothing is designed with real baby growth in mind. Fits are created to feel comfortable from the first wear and continue fitting as babies grow, rather than feeling restrictive.
This allows parents to confidently choose sizes that prioritize comfort, movement, and longer wear.
Why Parents Trust Lunakit Baby
- Free EU shipping (3–7 days)
- Comfortable, baby-friendly fits
- Designed for movement and growth
- Easy returns for peace of mind
- Premium European-inspired quality
Frequently Asked Questions
Should I size up if my baby is between sizes?
Yes. Choosing the bigger size ensures better comfort and longer wear.
Is it normal if baby clothes look a bit big at first?
Absolutely. Babies grow quickly, and slightly bigger clothing becomes ideal fast.
Are size charts reliable?
They are helpful, but comfort and fit should always come first.
Will bigger clothes affect my baby's movement?
No. Bigger sizes usually improve movement rather than restrict it.
Final Thoughts
Choosing baby clothing size by age alone often leads to frustration. Prioritizing height, comfort, and growth — and choosing a slightly bigger size — gives your baby room to move, grow, and stay comfortable longer.
👉 Explore our Baby Clothing Collection to find thoughtfully designed pieces that support comfort, movement, and growing babies.