Baby age, week by week
12 Weeks Old — How Many Months?
A 12-week-old baby is 84 days old — about 2 months and 23 days.
This week
Three months near! Many babies laugh out loud now, and hands live in the mouth.
The math
12 weeks = 84 days ≈ 2 months + 23 days
A month is longer than 4 weeks — on average 30.44 days — so you can't just divide by 4. The exact answer shifts a little with the calendar, so for the day-perfect number, use the calculator with your baby's real birthday.
Get the exact age →What babies do around week 12
At 12 weeks your baby is near the 3 Months mark. Around this age, many babies:
- Lifts their head and chest when lying on their tummy
- Watches faces closely and follows moving things
- Smiles at people all on their own