Free parent tool
Baby Growth & Development by Age: 0–12 Months
Choose your baby’s age once. See a simple snapshot of sleep, feeding, little firsts, teething and size around now. Open any section when you want the full guide.
Slide to any month from birth to 12 months.
Every baby is different. These are general reference ranges and milestone checkpoints, not targets or a diagnosis.
Growing & changing
Teething, clothing and diaper fit
Teething
No teeth usually yet
The first tooth commonly appears from about 6 months, though timing varies widely.
Clothing
UpBox age range 3–6 months
Typical reference range: 6–8 kg · 13–18 lb and 61–67 cm · 24–26 in. Clothing labels vary, so use your baby’s actual fit first.
Diapers
Go by weight, not age
Brand weight ranges overlap and differ. Check the pack and your baby’s current fit.
Feeding
Milk, solids and texture
Right now
Milk only
Breast milk or infant formula is the main nutrition at this age. Solid food usually begins at about six months, when your baby shows signs of readiness.
Follow hunger and fullness cues.
Need milk amounts?
Use the dedicated milk guide
For expressed breast milk or formula estimates, use the separate guide rather than relying on age alone.
Sleep
Typical patterns around this age
3 to 4 months
Sleep is still changing quickly
Sleep starts to organise. A daytime rhythm and longer nights begin to emerge.
Newborn sleep varies widely. Use the full sleep guide for the detailed ranges and context.
Little firsts
Next CDC milestone checkpoint
By 4 months
Finding their voice
CDC milestones are checkpoints, not a score. Here are a few things listed by this checkpoint.
- Smiles on their own to get your attention
- Chuckles when you try to make them laugh
- Looks, moves, or makes sounds to keep your attention
- Makes cooing sounds like oooo and aahh
Health visits
Keep the schedule in one place
Vaccinations
See the India schedule
Use the full vaccination tool for routine age-based visits rather than a shortened list here. Your child's actual schedule should be confirmed with their doctor.
They don’t just outgrow clothes. What they need changes too.
We’ve already done the looking. See useful things for where they are now.
This page brings together short summaries from separate UpBox tools. Use the linked full guides for the detail and sources behind each topic. Clothing and diaper sizing varies by brand, so fit and the manufacturer’s size information should guide the final choice.