Short answer: Babies develop movement skills in a broadly predictable order, but at very different speeds. According to the US Centers for Disease Control and Prevention (CDC), most babies roll from tummy to back by 6 months, sit without support by 9 months and take a few steps on their own by 15 months — and many do these things earlier. Crawling isn't a compulsory stage. Daily tummy time and plenty of floor play help most. Talk to your health visitor or doctor if your baby loses skills, seems very floppy or stiff, uses one side much more than the other, or is well behind these markers.
At the birthday party, your relative's baby is already walking across the room. Yours, two weeks older, is sitting happily on the floor studying a crumb. And your mind starts racing.
The order matters more than the timing
Movement skills tend to build on each other: head control, then rolling, sitting, getting around, pulling to stand, cruising and walking. The age range for each step is wide. A baby who walks at 16 months will usually be running around just like a baby who walked at 10 months a couple of years later.
Development isn't a race with a winner. It's a route every child travels at their own pace.
What most babies do by…
The CDC's milestones describe what most children (around three in four) can do by a certain age. Many reach them sooner.
- 6 months: rolls from tummy to back, pushes up on straight arms during tummy time, leans on hands when sitting, reaches for a toy.
- 9 months: gets into a sitting position alone, sits without support, passes things from hand to hand.
- 15 months: takes a few steps on their own, stacks two small objects, feeds themselves some food with their fingers.
- 2 years: walks up a few stairs, with or without help.
Crawling isn't compulsory
Some babies never crawl. They bottom-shuffle, roll across the room, or go straight to pulling up and walking. That isn't a problem in itself, as long as they're finding ways to move and using both sides of their body.
What helps
Tummy time from birth
The NHS recommends tummy time from birth, when your baby is awake and you're watching. Start on your chest, little and often, and build up. It strengthens the muscles needed for sitting and crawling. The UK activity guidelines suggest at least 30 minutes of tummy time spread through the day once babies are able.
Floor time over seats
Bouncers, car seats and baby walkers restrict movement. The NHS notes that baby walkers and bouncers encourage babies to stand on tiptoe and can delay walking if used a lot; if you use them, keep it to no more than 20 minutes at a time. A mat on the floor with toys just out of reach does more.
Bare feet indoors
Being barefoot at home helps babies feel the floor and practise balance. Shoes are for protection outdoors once your child is walking.
Active play every day
Once walking, toddlers need at least three hours of activity a day, spread through the day, including outdoor play.
When to talk to someone
Talk to your health visitor or doctor if your baby:
- loses skills they already had — the most important sign on this list;
- feels very floppy or very stiff;
- clearly uses one side of the body or one hand much more than the other;
- is well behind the milestones above — for example not sitting without support by 9 months or not taking steps by around 18 months;
- was born early and you're unsure what to expect (use their corrected age).
In the UK, health visitors offer regular development reviews until around age two. Asking early isn't over-worrying: if extra help is needed, such as physiotherapy, starting early helps. And most of the time you'll be reassured.
Related reading
Play ideas for every stage: Play is Learning (PDF, English) has 150 developmental activities for 0- to 4-year-olds using things you already have at home.
Sources
- Centers for Disease Control and Prevention — CDC's developmental milestones.
- NHS — Keep your baby or toddler active.
- NHS — Physical activity guidelines for children under 5.
- NHS — Baby reviews.
Written by the Bloom Guides editorial team. Last updated: 20 October 2026. General information only — not a substitute for advice from your health visitor or doctor.