When do babies sit up?

Sitting up gives your baby a bigger perspective on the world and lets them play and grab for toys in a totally new way.

Learning to sit up is a process, and it's not easy. Your baby's back, neck, and core muscles need to be strong enough to keep them upright, and they'll need to balance and figure out where to put their legs to keep from toppling over.

When do babies sit up?

Sitting up with support: By the time your baby is 4 to 5 months old, they'll probably be able to hold their head steady and sit up with support. To help your baby learn to sit, put them in your lap and let them lean back on you (or support them with your hands) when you're sitting together on the floor. Or, you can prop your baby up with pillows. (Some C-shaped breastfeeding pillows work well for this purpose.)

The slightest movement could make your baby topple over, so keep close to your little one when they're sitting propped up. Once they're sitting supported, babies soon learn to "tripod," which means leaning forward on their hands to balance.

Sitting up on their own: By 6 to 8 months old, most babies can sit up without support or help from you, and without leaning on their hands for balance. They may wobble a bit, but they will have learned how to sit independently.

They may not be able to get smoothly from lying down to sitting up (and vice-versa) just yet. Even babies who've mastered sitting will topple over eventually, often because they lose interest in being upright and don't know how to change positions.

How babies learn to sit up

Newborns

Your baby is far away from sitting up with or without support. However, you can start preparing them with plenty of tummy time. At first, the most they'll do is try to lift their head – and that's good! They're strengthening their back and neck muscles and practicing the skills they'll need to start sitting up.

1 to 2 months

As your baby gains better head control from all that tummy time, you'll notice they can lift their head higher and even turn it side to side. This is exactly the type of exercise your baby needs to tackle sitting up within the next few months.

3 to 4 months

Starting around now, you'll see a big improvement in your baby's neck strength and head control. They'll learn to raise their head to 45 degrees and keep it steady while lying on their stomach. By 4 months old, many babies use their arms to hold their head and chest off the ground in a "mini pushup." Some babies will start rolling over from tummy to back.

5 to 6 months

Your baby will get used to sitting with support, and will be probably be able to sit well in a high chair or baby floor seat. Make sure to use the seat belt to keep your baby secure. Also, once your baby can sit in a highchair and shows other signs of readiness, you can start giving them solid foods.

Your baby will probably also learn to roll over from back to tummy, which takes more strength and coordination.

7 to 8 months

After sitting with support, your baby will figure out how to maintain their balance while seated by leaning forward on one or both hands in a tripod position. By 7 to 8 months old, they'll probably be able to sit unsupported (which will free their hands for exploring), and they'll learn how to pivot to reach a desired object while sitting.

9 months and older

At this point your baby will be able to sit well, and will figure out how to get in and out of a sitting position.

How to help your baby sit up

You can help your baby reach this milestone by:

• Giving your baby plenty of tummy time. Lifting their head and chest helps your baby strengthen their neck muscles and develop the head control necessary for sitting up.
• Encouraging your baby to look up during tummy time. Use a bright toy that makes noise to prompt them to look up. (This is also a good way to make sure that your baby's hearing and vision are on the right track.)
• Letting your baby practice sitting up supported by pillows or leaning against you. Once your baby is used to this, put toys and other intriguing objects within their reach to make sitting up even more fun.

As always, and especially when they're just learning to sit, be sure to stay close to your baby in case they topple over – or want to show off their new skill. Have them practice sitting on a soft, carpeted floor or blanket, or outside on a picnic blanket.

What to do if your baby doesn't sit up

Babies develop skills differently, some more quickly than others. But any time you suspect a problem with your baby's development, it's best to act early and get help, if needed, with any developmental delays.

Talk to your baby's doctor if they

• Can't hold their head up steadily by the time they're about 4 months old
• Can't sit with help by 6 months old
• Can't sit unsupported by 9 months old

Keep in mind that premature babies may reach this and other milestones later than their peers.

After your baby starts sitting up, what's next?

Sitting is the key to crawling, standing, and walking. After your baby reaches this milestone, it's probably just a matter of time until they move on to crawling.

Your baby will figure out that they can lunge forward from a sitting position and balance on hands and knees. They may get the hang of moving forward (or backward) on all fours as early as 6 or 7 months old, and master crawling by 10 months.

Some babies use other ways to get around, like scooting on their bottom, slithering on their stomach, or rolling across the room. Others don't ever crawl and move directly to pulling up, standing, cruising, and walking.

One note: As your baby gets increasingly mobile, good babyproofing is crucial!