Baby Development by Month
What to expect every month from newborn to age 3: weight and length ranges, milestones, sleep and feeding in one place.
First year: 0-12 months
From reflexes to first steps. Smiles, rolling, sitting, solids and first words.
NB NewbornWelcome to the world, little one! The first days are all about adjustment.2.5 - 4.0 kg · 46 - 53 cm 1 1 month oldYour baby is starting to recognize the world and show first social reactions.3.4 - 5.8 kg · 50 - 57 cm 2 2 month oldFirst smiles are coming! Your baby is becoming more social.4.3 - 7.1 kg · 53 - 61 cm 3 3 month oldYour baby is now more social and interactive. You may hear first laughs!5.0 - 8.0 kg · 56 - 64 cm 4 4 month oldMotor skills are developing fast. Baby reaches for and grabs objects.5.7 - 8.7 kg · 58 - 66 cm 5 5 month oldYour baby is very curious about the world and wants to explore everything!6.0 - 9.2 kg · 60 - 68 cm 6 6 month oldA big milestone: time to start solids!6.4 - 9.8 kg · 62 - 70 cm 7 7 month oldYour baby is preparing to crawl and actively exploring surroundings.6.7 - 10.2 kg · 64 - 72 cm 8 8 month oldCrawling begins! Your baby is very active now.7.0 - 10.5 kg · 65 - 73 cm 9 9 month oldYour baby is building problem-solving skills.7.2 - 10.9 kg · 67 - 75 cm 10 10 month oldFirst steps are near! Cruising along the furniture.7.5 - 11.2 kg · 68 - 77 cm 11 11 month oldAlmost one year old! Your baby now feels like a little individual.7.7 - 11.5 kg · 69 - 78 cm 12 12 month oldCongratulations! Your baby is 1 year old! What an incredible year.7.9 - 12.0 kg · 70 - 80 cm
Second year: 13-24 months
Walking, the word explosion and the "I do it myself" phase.
13 13 month oldBabyhood is behind, walking adventure ahead — every day a new discovery!8.2 - 12.1 kg · 71 - 81 cm 14 14 month oldCuriosity peaks — your mini explorer heads straight for the cabinets!8.4 - 12.4 kg · 72 - 82 cm 15 15 month oldWord explosion approaches — expect 2-3 new words a week.8.6 - 12.7 kg · 73 - 84 cm 16 16 month oldImagination blooms — baby puts doll to sleep, feeds spoon to you.8.8 - 13.0 kg · 74 - 85 cm 17 17 month oldRunning begins — a tiny athlete full of energy!9.0 - 13.3 kg · 75 - 86 cm 18 18 month old18-month checkup + the boosters due at this age — a critical developmental month.9.1 - 13.7 kg · 76 - 88 cm 19 19 month old"I'll do it!" era — resistance is actually a sign of independence.9.3 - 14.0 kg · 77 - 89 cm 20 20 month oldAnimals, vehicles, colors — learning new words every day.9.5 - 14.3 kg · 78 - 90 cm 21 21 month oldTwo-word sentences grow: "mommy come", "drink water", "go outside".9.7 - 14.6 kg · 79 - 91 cm 22 22 month oldImitation play peaks — pretend phone calls, driving, cooking.9.9 - 14.9 kg · 80 - 92 cm 23 23 month oldSecond birthday nearing — language and movement grow together.10.1 - 15.2 kg · 81 - 93 cm 24 24 month oldAge 2! A major transition — language, movement and independence all peak.10.2 - 15.6 kg · 82 - 94 cm
Third year: 25-36 months
Sentences, imagination, games with rules and getting ready for preschool.
25 25 month oldBrain forms millions of new connections per second — every experience matters.10.4 - 15.9 kg · 83 - 95 cm 26 26 month oldCreativity grows — drawing, dreaming, telling stories.10.5 - 16.2 kg · 84 - 96 cm 27 27 month oldBalance and coordination grow — tricycle time is near.10.7 - 16.5 kg · 85 - 97 cm 28 28 month oldColors, numbers and shapes enter daily life.10.8 - 16.8 kg · 86 - 98 cm 29 29 month old"Why?" all day long — the tree of curiosity branches out.11.0 - 17.1 kg · 86 - 99 cm 30 30 month old2.5 years — language and social skills grow fastest now.11.1 - 17.4 kg · 87 - 100 cm 31 31 month oldJoining rule-based games — turns, winning and losing begin.11.3 - 17.7 kg · 88 - 101 cm 32 32 month oldDrawings now represent things — symbolic thinking develops.11.4 - 18.0 kg · 89 - 102 cm 33 33 month oldHumor develops — jokes, deliberate wrong answers, laughter...11.5 - 18.2 kg · 90 - 103 cm 34 34 month oldLetters, numbers, patterns catch their attention — pre-school begins.11.7 - 18.5 kg · 90 - 104 cm 35 35 month oldOn the threshold of age 3 — independence is now a core trait.11.9 - 18.8 kg · 91 - 105 cm 36 36 month oldCongratulations! Age 3 — no longer a baby, now a little child. Character foundation is laid!12.0 - 19.0 kg · 92 - 106 cm