Children burn a large number of calories simply by growing, playing and going about their day-to-day lives. Caloric requirements for children vary according to rate at which they burn calories, their body type and their age. Average calorie needs increase as a child ages, with his peak number of calories -- between 2,200 and 3,000 daily calories -- during adolescence. Caloric requirements for children are largely based on a certain number of calories in relation to a child's body weight. The "Merck Manuals" discusses nutritional needs for infants and children, and uses a formula of kcalories -- kilocalories, what are usually called nutritional calories, or just calories--per pound of body weight.
Babies and Toddlers
The "Merck Manuals" suggested formula for an infant required daily calories equals 50 to 55 calories per pound up to 6 months of age, and drops to 45 calories per pound for 1-year olds. During infancy and into the toddler years -- around age 3 -- calorie requirements are the same for boys and girls. Online health resource KeepKidsHealthy.com reports the average number of daily calories required by infants up to 5 months old are about 650 calories. The number of calories needed to sustain normal development incrementally increases as a baby approaches his first birthday and second birthday. One year olds generally need about 850 calories each day. Children between the ages of 1 and 3 consume roughly 1,300 calories daily.
4 to 8 Years Old
Starting as early as 4 years old, children's caloric requirements may differ according to their sex. Generally speaking, boys require a higher calorie intake than girls, as reported by the National Heart, Lung and Blood Institute, or NHLBI, but each child's needs vary according to activity level. Gender differences and calorie intake diverge for most of a person's life, though calorie requirements drop once a person hits adulthood. The NHBLI estimates that 4- to 8-year-old boys require between 1,400 and 2,000 daily calories, depending on their activity level, while girls need approximately 200 calories less than boys for each development stage and activity level.
The NHLBI defines "active" as performing the equivalent of walking at least three miles each day, at a rate of 3 to 4 miles per hour. At this age, "active" may include running around at recess and participating in physical education at a high effort level. Sedentary is classified as being involved in "day to day" activities, such as eating, going to school and going through a typical daily schedule with not a lot of extra activity.
9 to 13 Years Old
The "tween" age, between 9 and 13, is a time for growing and approaching puberty. Children in this age group continue to require large numbers of calories to support their growth and sustain their body weight. The NHLBI recommendations for caloric intake for 9- to 13-year-old boys are 1,800 to 2,600, with more active boys weighing in at the higher end of the scale. Girls in this age group generally need to consume 1,600 to 2,000 daily calories. Baylor School of Medicine offers a calorie needs calculator to help parents determine their child's approximate caloric requirements based on age, body type and activity level.
The USDA Dietary Guidelines for Americans 2010 show that children hit their peak in terms of caloric requirements in their teen years, between the ages of 14 and 18 years old. Kids in this age group are typically active with sports and other school-related activities, and approach their full height. Boys that function at a high activity level during their teen years usually require between 2,800 and 3,200 calories daily, with girls close behind in the 2,400 calorie range. Boys who are more sedentary may only need to consume 2,200 to 2,400. Girls with a less active lifestyle typically require 1,800 to 2,000 calories daily. The "Merck Manuals" uses a formulation of 20 calories per pound when determining caloric requirements for middle teens, around 15 years of age.