Your baby at six months: development, starting solids and the six-month check

3-6 months · Development · Reviewed 20 June 2026 · All articles

Six months is one of those moments that feels like a real turning point. Your baby has changed more dramatically in this half-year than at any other period in their life, and the next six months will bring changes just as extraordinary. This article walks through what to expect around the six-month mark: growth, movement, feeding, sleep, senses, and the checks your health team will carry out. Remember throughout that these are typical ranges for most babies, not all. Every baby moves at their own pace, and a wide range of development is normal and healthy.

Development at a glance

• Typical weight: around 7.5 to 8 kg (roughly double birth weight for most babies, though this varies)
• Typical length: around 65 to 68 cm
• Head circumference: around 42 to 44 cm
• Motor milestones: rolling confidently in both directions, beginning to sit briefly without support, pushing up on hands during tummy time, bouncing when held standing
• Communication: babbling with consonant sounds (ba, da, ma), laughing, squealing
• Social: recognises familiar faces and voices, shows clear preferences for known caregivers
• Feeding: ready to begin or just beginning solid foods alongside continued breast milk or formula

Physical development

By six months most babies have roughly doubled their birth weight, though the exact number varies considerably from baby to baby. A baby born at 3.5 kg might weigh anywhere from 6.5 kg to 9 kg at six months and be growing perfectly well. What matters is the trend on your baby's centile chart, not a single measurement.

Length increases of around 15 to 17 cm over the first six months are common. Your baby's head will also have grown significantly as their brain develops rapidly. Your health visitor or paediatrician will track all three measurements together.

Motor skills

Rolling is now typically confident and purposeful in most babies. Many babies roll from back to front and front to back, using rolling as a way to get closer to interesting objects. This is the start of mobility, and you will notice your baby beginning to move around a mat or blanket in ways that can surprise you.

Sitting is an emerging skill at six months. Many babies can sit for short stretches without support if placed in a sitting position, though they will topple over if they reach too far or lose concentration. Most will need a steadying hand or a V-shaped cushion for longer sitting sessions. Full independent sitting, where a baby can get into a sit on their own and stay there reliably, typically comes a little later, often between seven and nine months.

Tummy time is important at this age for building the core and neck strength that underpins crawling. If your baby tolerates it well, aim for several short sessions across the day. Many babies start to push up on extended arms or even rock on their hands and knees, which are early signs that crawling is not far away.

When held in a standing position, many six-month-olds will bounce enthusiastically and bear some weight through their legs. This is great for leg strength and is completely safe, provided you are supporting their trunk.

Hands and reach

Hand control is much more deliberate now. Your baby can reach accurately for objects, transfer them from hand to hand, and bring them to their mouth for exploration. The mouth remains one of the primary tools for understanding new objects, so anything within reach is likely to be mouthed, which is worth keeping in mind as mobility increases.

Feeding and starting solids

Around six months is the recommended time to introduce solid foods, and for many families this feels like one of the bigger milestones of early parenthood. The timing is not arbitrary: it aligns with the point at which most babies have the physical readiness for swallowing, the digestive maturity to handle foods other than milk, and the nutritional need for additional iron and zinc that milk alone can no longer fully meet.

The three readiness signs

Rather than going by age alone, look for all three of the following signs of readiness:

1. Able to sit with minimal support and hold their head steady. A baby needs to be upright to eat safely.
2. Loss of the tongue-thrust reflex. Young babies automatically push anything other than a nipple or teat back out of their mouth. When this reflex has faded, they can move food to the back of the mouth to swallow.
3. Interest in food. Your baby watches you eat, reaches toward food, or opens their mouth when food is offered.

Starting before four months is not recommended, and there is good evidence that waiting until you see all three signs, even if that means waiting until six and a half or seven months, leads to better outcomes. For a full guide to first foods, approaches, textures, and what to expect in the early weeks of weaning, see our detailed article on starting solids around six months.

Milk continues to be the main food

A common misconception is that once solids start, milk becomes less important. In fact, breast milk or infant formula remains the primary source of nutrition throughout the first year. Solids are introduced alongside milk, not instead of it. In the first weeks of weaning, the quantities of solid food your baby takes will be very small and the nutritional contribution will be minimal. The purpose in those early weeks is exploration, learning to swallow different textures, and building a relationship with food.

Iron-rich foods from the start

Iron deserves particular attention at weaning. The stores of iron your baby was born with, laid down in the final weeks of pregnancy, are largely depleted by around six months. Breast milk is low in iron, and standard infant formula is fortified but may not fully meet needs as the baby grows. From the very beginning of weaning, including iron-rich foods is important. Good sources include pureed or minced meat and poultry, cooked lentils and legumes, iron-fortified infant cereals, and dark leafy vegetables such as spinach. Vitamin C consumed at the same meal helps the body absorb non-haem (plant) iron more effectively.

Sleep at six months

Sleep at six months is one of the most variable aspects of baby development, and it is one of the topics parents ask about most. The honest answer is that there is a wide normal range and what you are experiencing is almost certainly within it.

Some babies sleep long stretches at night by six months. Many still wake once or twice. A smaller number wake more frequently. All of these patterns can be normal. Sleep is shaped by a combination of developmental stage, hunger, temperament, feeding method, and environment, and it does not follow a simple timetable.

Naps are typically settling into a pattern of two daytime sleeps by six months, usually one in the morning and one in the afternoon, though some babies still take three shorter naps. Total sleep in 24 hours is typically around 12 to 15 hours, split between night and day, but again there is wide variation.

If night waking is significantly affecting your wellbeing, it is worth discussing this with your health visitor. There are gentle approaches that can help with sleep consolidation if and when you feel ready to try them. There is no single correct approach, and there is no rush to change anything that is working for your family.

Health, senses and the six-month check

The six-month health review

In many places, a health visitor or community nurse will carry out a developmental review around six months. This typically includes a check of physical growth (weight, length, head circumference), a look at motor development, a hearing check or parent-reported hearing concerns, and an opportunity to raise any feeding or sleep questions. It is also a good time to discuss weaning if you have not yet started.

If you have not yet had a six-month review scheduled, contact your health visiting team or GP surgery to arrange one. These checks are valuable not because anything is expected to be wrong but because they provide a documented baseline and a dedicated opportunity to ask questions in a low-pressure setting.

Vision and hearing

By six months most babies have excellent near and far vision. Your baby can now recognise a familiar face from across a room, track moving objects smoothly with their eyes, and show a clear preference for faces over other visual stimuli. Depth perception has developed significantly, which is part of why babies this age can reach accurately for objects.

Hearing is also well developed. Your baby will turn their head toward the source of a sound and may show different reactions to familiar voices compared to unfamiliar ones. Localisation of sound, knowing which direction a noise came from, is now accurate in most planes.

Babbling and communication

Babbling typically begins around four to six months and is often well established by the six-month mark. You will hear repeated consonant-vowel combinations: ba-ba, da-da, ma-ma. These sounds are not yet words with meaning, but they are the foundation of language. Responding to babble as though it is conversation, taking turns, making eye contact, and mirroring the sounds your baby makes are all ways of supporting language development.

Your baby is also communicating through body language: leaning toward things they want, turning away from things they do not want, and showing distinct facial expressions for pleasure, frustration, and curiosity. These are early forms of intentional communication worth noticing and responding to.

Social and emotional development

Six months is typically when babies show strong social preferences. Your baby knows who their primary caregivers are and shows this clearly: they may reach toward familiar people, calm more quickly in familiar arms, and show visible happiness at the approach of known faces. Stranger wariness, sometimes called stranger anxiety, may be beginning to appear or will arrive in the coming months.

This preference for familiar people is healthy attachment behaviour, not a problem to be solved. It is a sign that your baby has formed secure bonds.

What comes next: seven to nine months

The months ahead bring some of the most visible physical changes of early babyhood. Crawling, in one of its many forms, typically appears somewhere between seven and ten months for most babies. Some babies commando-crawl on their belly, some shuffle on their bottom, some move in ways that seem to defy description, and some move straight to pulling to stand without a classic crawl phase at all. All of these are normal paths toward independent mobility.

Sitting becomes more confident and independent. Your baby will begin to pull to stand with support, which marks the beginning of the long road to walking. Fine motor skills will also advance: the pincer grip, using the thumb and index finger to pick up small objects, typically emerges between eight and ten months.

Language development accelerates over this period. Babbling becomes more varied and more clearly directed at people. By nine months many babies show early signs of understanding some words or phrases, particularly those used consistently in daily routines.

Solid foods will expand considerably. Starting with smooth purees or soft finger foods, most babies are eating a range of textures and flavours by nine months. The goal of weaning through this period is variety, which supports both nutrition and the development of a flexible relationship with food.

Frequently asked questions

When should I start my baby on solid foods?

Most health guidelines recommend introducing solid foods at around six months, once your baby shows all three readiness signs: they can sit with minimal support, they have lost the tongue-thrust reflex (they do not automatically push food out of their mouth), and they show interest in food by reaching or leaning toward it. Starting before four months is not recommended, and starting after seven months can make acceptance of new textures harder. Always continue breast milk or formula as the main source of nutrition through the first year.

How much should a six-month-old weigh?

A typical six-month-old weighs somewhere between 6.5 kg and 9 kg, with an average around 7.5 to 8 kg. Most babies have roughly doubled their birth weight by this point. Weight is just one measure of healthy growth, and your health visitor or paediatrician will plot your baby on a centile chart to look at the trend over time rather than focusing on a single number. Wide variation is completely normal.

Why is iron so important when starting solids?

Babies are born with iron stores laid down during pregnancy. Those stores are largely depleted by around six months, which is one reason that six months is the recommended time to begin weaning. Breast milk and standard infant formula contain limited iron, so offering iron-rich first foods such as pureed meat, lentils, fortified cereals, and dark leafy vegetables helps bridge the gap. Pairing iron-rich foods with a source of vitamin C can improve absorption.

Is it normal for a six-month-old to still wake at night?

Yes, night waking at six months is completely normal and very common. Some babies sleep through by this age, but many still wake once or twice. Sleep at six months is shaped by developmental changes, hunger, and temperament rather than habit alone. There is no single correct approach to night waking. If your baby is gaining weight well and you are managing, there is no urgency to change anything. Talk to your health visitor if night waking is significantly affecting your wellbeing.