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Baby month by month

A simple guide to your baby's first year. Pick your baby's age to see what they may be doing, how much they sleep, how to feed them and how to keep them safe.

Before you use this guide: This is general educational information, not an individual medical assessment. Every baby develops at their own pace. If you are worried about your baby, talk to your doctor or health visitor.

1 monthFocusing on faces, startle and grasp reflexes 2 monthsSocial smiles, cooing, brief head lifting 3 monthsHead control, giggles, finding their hands 4 monthsLaughing, holding toys, steady head, sleep changes 5 monthsRolling, reaching, babbling, sitting with support 6 monthsFirst foods, sitting, rolling, babbling 7 monthsSitting, passing toys, babbling strings of sounds 8 monthsCrawling or scooting, peekaboo, separation anxiety 9 monthsSitting alone, crawling, pulling up, “mamama”10 monthsCruising, clapping, waving, understanding “no”11 monthsStanding, first steps, first words, pointing 12 monthsFirst steps, first words, cow's milk

The first year at a glance

Typical weight and sleep by age in months
Age	Median weight (boys · girls)	Sleep in 24 hours
1 month	4.5 kg · 4.2 kg	14 to 17 hours
2 months	5.6 kg · 5.1 kg	14 to 17 hours
3 months	6.4 kg · 5.8 kg	14 to 17 hours
4 months	7.0 kg · 6.4 kg	12 to 16 hours
5 months	7.5 kg · 6.9 kg	12 to 16 hours
6 months	7.9 kg · 7.3 kg	12 to 16 hours
7 months	8.3 kg · 7.6 kg	12 to 16 hours
8 months	8.6 kg · 7.9 kg	12 to 16 hours
9 months	8.9 kg · 8.2 kg	12 to 16 hours
10 months	9.2 kg · 8.5 kg	12 to 16 hours
11 months	9.4 kg · 8.7 kg	12 to 16 hours
12 months	9.6 kg · 8.9 kg	11 to 14 hours

Weights are WHO child growth standard medians at the start of each month. At birth the medians are 3.3 kg for boys and 3.2 kg for girls. Healthy babies are often well above or below these figures.

How to use these guides

Each page covers one month of age. For example, the 4 month page covers the time from when your baby turns four months old until they turn five months. Use it as a guide to what is common, not a checklist to pass.

Born early? Use your baby's corrected age for milestones. Our corrected age calculator works it out from the due date.
Milestones: The skills listed come from public checklists, such as those from the US CDC, plus common experience. They describe what many babies do, and there is a wide healthy range.
Growth: Your baby's growth is plotted on centile charts in their personal health record. The NHS advises weighing no more than once a month up to six months, and no more than once every two months from six to twelve months, unless there is a concern.

Key moments in the first year

1 month: getting into a feeding rhythm, with most babies back to birth weight.
2 months: first social smiles and often the first vaccinations.
4 months: laughing, reaching, and the 4 month sleep regression.
6 months: starting solid foods alongside milk.
9 months: crawling, pulling to stand and separation anxiety.
12 months: first steps, first words and cow's milk.

When to ask for help

Talk to your doctor or health visitor if your baby loses skills they had, does not respond to sounds or to people, seems very stiff or very floppy, is not feeding or gaining weight, or if you simply have a worry that will not go away. A temperature of 38 °C or above in a baby under three months needs urgent medical advice. Read our guide to baby fever and illness and our guide to vaccinations and check-ups.

Also useful: all baby care guides, feeding guides, our guide to wake windows by age and the newborn essentials checklist.

This content is for general information only and is not medical advice. Every pregnancy and every baby is different. Always talk to your doctor, midwife or paediatrician about your own situation, and seek urgent care if you are worried.