Baby milestones & development: When do babies start sitting up?

By Debra Silver, Paediatric Physiotherapist at Kidswell Health

Watching your baby reach new milestones is one of the most exciting parts of early parenthood. From their first smiles to their first steps, every stage shows how their strength, balance, and coordination are developing.

One of the biggest milestones parents look forward to is when their baby starts sitting, but exactly when do babies start sitting up on their own? Here’s what to expect and how you can help.

When do babies start sitting up?

Most babies start sitting with support between 4 and 6 months, and can usually sit up on their own by around 7 to 9 months.

At first, your baby might prop themselves up with their hands (“tripod sitting”) before developing the balance and strength to sit independently. This is a normal and important part of physical development.

Every baby develops at their own pace, so don’t worry if your little one takes a bit longer. Factors such as prematurity, muscle tone, and time spent practising movement can all influence when babies learn to sit up.

If your baby isn’t sitting by 9 months, or you’re unsure about their progress, you can speak with your GP or a paediatric physiotherapist for reassurance and tailored advice.

When do babies sit up on their own?

Most babies are able to sit up on their own between 7 and 9 months. At this stage, they can balance without using their hands for short periods and reach for toys while staying upright.

By around 9 months, many babies can move into a sitting position from lying down – an exciting sign of developing core strength and coordination.

If you’re wondering when babies learn to sit up, it’s all part of a gradual process involving rolling, pushing up, and building muscle control through play.

How to help your baby sit up

The good news is there’s plenty you can do at home to support their motor development safely and naturally:

• Tummy time: Encourage short, regular sessions from birth to build neck, shoulder, and core strength.
  
• Supported sitting: Around 4-6 months, let your baby sit on your lap or use cushions for gentle support.
  
• Floor play: Give your baby time to explore movement on a firm surface rather than keeping them in seats or carriers for long periods.
  
• Encourage reaching and turning: Place toys just out of reach to help develop balance and coordination.
  
• Keep it fun: Talk, sing, and play while they practise sitting – positive attention helps build confidence.
  

Signs your baby is getting ready to sit

You might notice these early signs that your baby is getting close to sitting up independently:

• Lifting their head and chest easily during tummy time
  
• Rolling both ways (front to back and back to front)
  
• Propping themselves up on their arms while lying down
  
• Trying to push up when reclined or lying flat
  
• Using their hands for balance while sitting supported
  

These small milestones are all part of your baby’s journey toward sitting independently.

When to seek advice

It’s always best to reach out for advice if you’re worried about your baby’s motor development. Contact your GP or a paediatric physiotherapist if your baby:

• Isn’t showing interest in sitting by around 9 months
  
• Feels unusually floppy or stiff when held
  
• Only uses one side of their body to reach or roll
  
• Has difficulty lifting their head during tummy time
  
• Seems delayed in other movement milestones, like rolling or crawling
  

Early support can make a big difference. A physiotherapist can assess your baby’s development, check muscle tone and posture, and guide you with exercises and play ideas.

How Kidswell Health can help

At Kidswell Health, our Paediatric Physiotherapist, Debra Silver, has over 15 years’ experience supporting babies and young children with movement and developmental concerns.

She can help with:

• Delayed sitting or crawling
  
• Tummy time difficulties
  
• Torticollis (neck muscle tightness)
  
• Positional talipes
  
• Hypermobility or flexible joints
  
• In-toeing or walking pattern concerns
  
• & Much more

Debra’s sessions are fun, interactive, and family-centred, focusing on early intervention to help every child reach their full potential.

Book a physiotherapy assessment

If you feel your child is struggling with their development and may benefit from physiotherapy, our expert team is here to help.

Based in Golders Green, North London, Kidswell Health provides specialist physiotherapy for babies and young children in a calm, child-friendly environment.

Find out more about our physiotherapy sessions or book an appointment today to learn more about how we can support your child’s development.