When do babies sit upright? What you need to know

Sitting up is a monumental rite of passage for babies and their parents. For many it is a sign of independence and growing up. My babies were much happier when they could sit up on their own. They could look around and observe their surroundings or have their hands free to play with toys. As one of the first major milestones of gross motor development, sitting is something to encourage with baby and something to look forward to.¹ You may be desperate for your baby to sit up, but aren’t sure when to expect this milestone and especially at what age babies sit up. You may also be wondering how you can help them achieve this goal and what to do if they aren’t quite where you think they should be. Here we’ll delve into all of that and more as we answer the question, “When do babies start sitting up on their own?”

So at what age do babies start sitting up on their own? Your baby should be able to sit in a supported seat by 6 months of age. This can be a three-legged sitting position in which they hold themselves upright while sitting by bending forward on their hands. This could also mean supporting them from the back or sides by holding them up or making sure they don’t fall over.²

According to the CDC, your baby should be sitting unsupported by 9 months of age. At this age, your baby should be able to sit up independently.³

In a large study of gross motor development, all babies were able to sit without support by around 9 months of age. The youngest baby, who could sit without support, was just below that 4 months old, and the oldest baby who sat was 9 months old. The average age of the babies in this study who sat without support was 6 months.¹

Before your baby can sit, he or she needs head control and core strength to stay upright. Signs of improvement in head control and core strength include measures such as:⁴

As your baby masters these skills, these may be signs that he or she is ready to start trying to sit up.

The infant’s strength develops from top to bottom, from head to feet. The first form of babysitting is the tripod sitting position. In this position they support their hands between their outstretched legs.⁴

As posture and strength develop, babies eventually learn to sit without the support of their hands, but are still working on balance and stability. They often have to catch themselves and can still often fall over.⁴

The final stage of sitting is the most stable – at this point babies can also maintain balance while twisting, turning their heads and moving their arms.⁴ I remember realizing that I was no longer worried about my toddler knocking my baby over from a sitting position because he had finally mastered sitting balance!

Here are some tips and tricks to help your little one practice sitting.

At my daughter’s four-month appointment, she rolled over and put her head in Tummy time, our pediatrician encouraged me to help my baby sit. She suggested I sit on the floor behind her and put my legs in a V shape so that she was supported from behind and sides. I also placed her hands on the floor so she could learn to support herself in the tripod sitting position.

For support, you can also place your baby in a sitting position and place your hands around their torso or ribs to hold them up. Over time, they will learn to balance with their torso or lean on one or both hands while looking around and playing with toys.²

Before my daughter could sit without support, I used a C-shaped seat to prop her up Nursing pillow behind her. I would sit across from her or place toys in front of her and encourage her to play with me while sitting and balancing. This encouraged her to sit and gave me reassurance that she wouldn’t fall backwards and hit her head on the floor.

I suspect this may have backfired in some ways. The pillow began to act as a safety net – she knew it was there and would do so throws himself intentionally from a sitting position straight back onto it. I’m sure she developed her core muscles largely by doing sit-ups outside of training Boppy pillowbut she learned the hard way (by falling backwards) that once she learned to sit and balance without support, the pillow wouldn’t always be there!

Several studies have shown a positive association between prone positioning and faster gross motor development. Babies who spent more time on their stomachs achieved sitting (both supported and independent). crawlAnd pull to get up in earlier years.⁵

Exercise and massage

In cultures that practice infant exercise and massage, babies sit younger on average. Parents are so confident in their stability that they move away from their baby when he or she is sitting.⁴

While parental support can be helpful, booster seats do not help a baby learn to sit independently. It may seem counterintuitive, but these baby containers distribute a baby’s weight poorly and put excessive pressure on the back and hips. These seats also restrict a baby’s movements and teach them to rely on these “chairs” for support. In addition, being tied to a baby seat immobilizes the baby’s joints and does not strengthen the muscles.⁶

So you have limited the amount of time your baby can spend in containers. I spent a lot of time practicing my stomach, provided endless support (literally!) and worked hard to encourage your baby to sit. Once you’ve mastered this skill, you’re probably wondering what might come next. Sitting is usually the next big gross motor milestone after rolling.⁴ It starts the cascade of strength, development and movement in the first 12 to 18 months of your baby’s life. Once they start sitting, other motor milestones can quickly follow.¹

A study of infant motor development showed that gross motor milestones follow a predictable order about 90% of the time. The following milestones to look out for after sitting include:¹

Infant motor milestones after sitting most often occur in the order listed above, but sometimes crawling and standing with support can be interchanged.¹

If your baby isn’t reaching these milestones or you’re worried, don’t hesitate to ask for help. Nobody knows your baby better than you! Trust your gut and always seek an evaluation from a trusted provider if you are concerned that your baby may not be meeting gross motor milestones. If your baby previously reached a milestone but no longer performs that action, this is also worth investigating.²

Your pediatrician should be able to perform a developmental screening and refer you to a specialist if necessary. It’s okay to get a second opinion if your pediatrician has no concerns but you’re still worried. You can often make an appointment with a pediatric physical therapist without a doctor’s referral. Finally, you could call your state Early intervention program for assessment and suitability. Therapy can make a significant difference, especially if initiated early.²

My second daughter was at the end of the “normal” level when it came to sitting and crawling. Her pediatrician assured me she wasn’t worried, but still gave me a referral for physical therapy. She reminded me that I know my baby best. I wasn’t afraid that she would never reach these milestones; However, I was interested in pursuing therapy to learn how to better help her achieve these goals and keep up with her peers.

In the time leading up to the appointment, we started practicing more supported sitting and motivation play. Ironically, just a few days before her physical therapy appointment, she started sitting and crawling independently, so I canceled it. However, I still remember that our pediatrician made me feel heard, supported and validated.

It can be emotional when your baby starts to sit! Once they start sitting, they seem less and less baby-like. As bittersweet as learning to sit may be for your baby, it is also an exciting milestone. It allows them to play with toys and see more of the world around them. There is a lot you can do to encourage sitting and if you are ever worried about it Developmental delay, your pediatrician is an excellent resource for further evaluation. With the right encouragement and intervention, your baby will sit (crawl, StandAnd go!) in no time.