Find the exact age in weeks since birth. Ideal for newborns and for anyone tracking a precise interval in weeks.
Newborn development moves so fast that pediatricians and parents track the first weeks precisely: feeding, weight gain, and sleep all change week to week. Week counting is also standard for pregnancy (40 weeks) and for tracking a newborn’s very early milestones.
The newborn period: feeding every 2–3 hours, sleeping up to 16–18 hours a day, and the first pediatric checkups at 1–2 weeks.
Babies begin to make eye contact, respond to voices, and have longer alert windows. Many parents track sleep and feeding in weeks.
First smiles, cooing, and head control improve. The 8-week vaccination visit is a common milestone marker.
By about 12 weeks babies start sleeping longer stretches at night. Around 3–4 months, most parents switch from weeks to months.
A newborn is usually considered to be 0–4 weeks old (the first month). After that, many parents switch to counting in months.
A pregnancy lasts about 40 weeks, and tracking by weeks lets doctors pinpoint fetal development and due dates far more precisely than months.
There are 52 weeks and 1 extra day in a common year (52 weeks and 2 days in a leap year).
Around 12 weeks (about 3 months), most parents switch from weeks to months as babies begin sleeping and feeding on a more stable schedule.