It is the growth plates, which are thin sections of bone, that actually do the growing. As your child continues to grow, their growth plates strengthen and become regular bone.

No child grows at a perfectly steady rate throughout this period of childhood, however. Weeks or months of slightly slower growth alternate with mini "growth spurts" in normal children. Children tend to grow a bit faster in the spring than during other times of the year.

0 – 1

The first year of an infant's life is a time of astonishing change. During this time, a baby will grow rapidly. On average, babies grow 25 centimeters in length while tripling their birth weights by their first birthday.

After age 1, a baby's growth in length slows considerably, and by 2 years, growth in height usually continues at a fairly steady rate of approximately 6 centimeters per year until adolescence.

2 – 3

During the third year of life, most toddlers gain about 1.8kg and grow about 5 – 8cm per year.

They're extremely active and mobile, and learning in very physical ways. They're sleeping less than they did in the year before, running around and exploring their world, and picking up new skills, like riding a tricycle.

Your toddler's appetite may fluctuate greatly now, which is common. Kids who are active, happy, and engaged and eat a variety of healthy foods are probably getting the nutrients they need and growing normally.

4 – 5

Children at this age are still very physical, but they learn in a more focused and less hectic way than when they were younger. These kids typically gain about 1.8kg and grow about 5 – 8cm per year. They're still developing and refining their gross motor skills, using their arms and legs to get around and to get what they want, as well as their fine motor skills, using their fingers, hands, and wrists for small movements, like picking up objects. By age 4, children can usually hop and eventually move on to skipping.

Play becomes increasingly imaginative and is an important part of kids' growth and development now. So it's important to make sure they have time for creative play — whether that means drawing pictures, running around in the backyard, or playing house.

6 – 12

As children grow from grade-schoolers to preteens, there continues to be a wide range of "normal" regarding height, weight, and shape.

Kids tend to get taller at a pretty steady pace, growing about 6 – 6.5 cm each year. When it comes to weight, though, they often start gaining weight faster at around 8 to 9 years of age.

This is also a time when children start to have feelings about how they look and how they're growing. It's common for girls in particular to worry about being overweight or "too big," while boys tend to be sensitive about being too short.

Try to help your child understand that the important thing is not to "look" a certain way, but rather to be healthy. Your child can't change the genes that will determine how tall they will be, but he can make the most of whatever height that is by developing healthy eating habits and being physically active.

Puberty

A major growth spurt occurs at the time of puberty.

Children usually enter puberty between age 8 to 13 years in girls and 10 to 16 years in boys. The average girl grows fastest between 12 and 13. Once girls start to menstruate, they usually grow about 2.5 – 5cm.

At their fastest, girls can grow taller by as much as 8cm a year and boys at a rate of 9cm a year. The average boy grows fastest between 13 and 15. Puberty lasts about 2 to 5 years. Growth is triggered in both boys and girls by increased levels of the sex hormone testosterone. This chemical also triggers the sexual organs to develop. The puberty growth spurt accounts for about 20% of our adult height. During this time as much as 10 – 30 cm will be gained in height.

By the time girls reach age 16-18 and boys reach age 16-20, the growth associated with puberty will have ended and they will have reached physical maturity although in boys especially their muscles may continue to develop.

Guess which bones can start growing first? The feet! So needing new shoes is the first sign. A teenager's developmental age can be measured by looking at the maturity of the bones in their hand and wrist. Next, arms and legs grow longer. The shin bones lengthen before the thigh, and the forearm before the upper arm. Finally the spine grows. The last expansion is a broadening of the chest and shoulders in boys, and a widening of the hips and pelvis in girls.