Baby age, week by week
31 Weeks Old — How Many Months?
A 31-week-old baby is 217 days old — about 7 months and 4 days.
This week
First crawls for some babies - though styles vary, and some skip crawling.
The math
31 weeks = 217 days ≈ 7 months + 4 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 31
At 31 weeks your baby is near the 7 Months mark. Around this age, many babies:
- Scoots on their belly or starts real crawling on hands and knees
- Finds a toy even when it's half hidden
- Deeply attached to their favorite people