About the Child Calorie Calculator
This calculator estimates how many calories a child or teenager needs each day to maintain healthy growth. It uses the Estimated Energy Requirement (EER) equations published by the US National Academies of Sciences, Engineering, and Medicine in 2023, which are based on doubly labelled water measurements of energy expenditure. They combine age, sex, height, weight and physical activity level, and add a small allowance for the energy used to build new tissue as children grow.
Use it as a planning guide for school lunches, sports seasons or a picky eater’s daily intake, or to understand why a growing teenager seems to be hungry all the time. The chart shows how needs change across the four activity levels so you can see the effect of a sports season or a quieter period.
EER equations describe the average needs of healthy children; individual needs vary by a few hundred calories either way. They are not designed for weight-loss or weight-gain plans. Children’s appetite is usually a good guide — if you have concerns about growth, weight or eating, talk to your pediatrician or a registered dietitian.
With the default inputs, the estimated calories per day is 1,673 kcal/day. Change any value above to recalculate instantly.
How to use the child calorie calculator
- 1Choose boy or girl and enter the child’s age.
- 2Enter current height and weight (from a recent check-up if possible).
- 3Pick the activity level that best matches a typical day.
- 4Read the daily calorie estimate and compare activity levels in the chart.
- 5Use it as a rough guide alongside your child’s appetite and growth curve.
Formula and method
The 2023 National Academies equations give a separate set of coefficients for boys and girls aged 3–18 at each of four physical activity levels. For example, a low-active boy uses EER = 19.12 + 3.68 × age + 8.62 × height + 20.28 × weight, and a low-active girl uses EER = −297.54 − 22.25 × age + 12.77 × height + 14.73 × weight, with height in centimetres and weight in kilograms.
A growth allowance is then added for energy deposited in new tissue: 20 kcal/day for boys aged 3, 15 kcal for ages 4–8 (and girls aged 3), 25 kcal for boys and 30 kcal for girls aged 9–13, and 20 kcal for ages 14–18. Children aged 1–2 use one equation per sex regardless of activity (boys −716.45 − 1.00 × age + 17.82 × height + 15.06 × weight + 20; girls −69.15 + 80.0 × age + 2.65 × height + 54.15 × weight + 15). The fat range applies the Acceptable Macronutrient Distribution Range (30–40% of calories at ages 1–3, 25–35% at 4–18) at 9 kcal per gram.
- age
- Age in years
- height
- Height in centimetres (inches × 2.54)
- weight
- Weight in kilograms (pounds × 0.4536)
- a, b, c, d
- Sex- and activity-specific coefficients from the 2023 NASEM report
Worked examples
8-year-old boy, 4 ft 2 in, 56 lb, low active
4 ft 2 in is 127 cm and 56 lb is 25.4 kg. The low-active boys’ equation gives 19.12 + 3.68 × 8 + 8.62 × 127 + 20.28 × 25.4 ≈ 1,658 kcal, plus a 15 kcal growth allowance, for about 1,673 kcal a day. If he were very active, his needs would rise to roughly 1,917 kcal; if inactive, about 1,583 kcal.
14-year-old girl, 160 cm, 50 kg, active
Using the active girls’ equation: −189.55 − 22.25 × 14 + 11.74 × 160 + 18.34 × 50 = 2,294.35, plus 20 kcal for growth, gives about 2,314 kcal a day. At a low-active level she would need about 2,191 kcal.
2-year-old toddler, 86 cm, 12 kg
For boys aged 1–2: −716.45 − 2 + 17.82 × 86 + 15.06 × 12 + 20 ≈ 1,015 kcal a day. Activity level does not change the toddler estimate.
Frequently asked questions
How many calories does a child need per day?+
The previous US Dietary Guidelines tables put needs at roughly 1,000–1,400 kcal for ages 2–3, 1,200–2,000 for ages 4–8, 1,400–2,600 for ages 9–13 and up to about 3,200 for active teenage boys. Size and activity explain most of the difference.
Why does the calculator need height and weight?+
The 2023 National Academies equations replaced age-only tables with equations that include height and weight, because bigger children burn more energy. This gives a more individual estimate than a single number per age group.
Should I count my child’s calories?+
Most healthy children regulate their intake well when offered regular meals and nutritious food. Strict calorie counting is generally not recommended for kids; use estimates for planning and talk to a pediatrician about weight concerns.
Why do teenage boys need so many calories?+
Adolescence brings rapid growth in height and muscle mass, and teenage boys are on average taller and heavier with more lean tissue, so both their resting and activity energy needs rise sharply between ages 12 and 18.
Can I use this to help my child lose weight?+
No. EER equations estimate the energy needed to maintain healthy growth. Weight management in children should be guided by a pediatrician, usually focusing on habits and activity rather than calorie restriction.
This tool gives general estimates and is not medical advice. Talk to a doctor or qualified professional about your health, diet or training.