Child Daily Calorie Needs Calculator
Estimates daily calorie needs for children and teens up to age 18 with the Institute of Medicine Estimated Energy Requirement (EER) equations, using age, sex, weight, height and activity level. Use it when planning a child's diet or monitoring healthy growth.
Last updated: September 2026
Formula below · 3 sources (dietaryguidelines.gov, healthychildren.org, aap.org) · Updated Sep 2026
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About this calculator
This calculator estimates the calories a child needs each day to maintain healthy growth. It uses the Estimated Energy Requirement (EER) equations of the Institute of Medicine Dietary Reference Intakes (2005), which were built from doubly-labelled-water measurements in children and include an allowance for growth. Ages 3–8: boys EER = 88.5 − 61.9 × age + PA × (26.7 × weight kg + 903 × height m) + 20; girls EER = 135.3 − 30.8 × age + PA × (10 × weight kg + 934 × height m) + 20. Ages 9–18 use the same equations with + 25 instead of + 20. The physical-activity coefficient PA is 1.00 (sedentary), 1.13 (low active), 1.26 (active) or 1.42 (very active) for boys and 1.00, 1.16, 1.31 or 1.56 for girls; this calculator maps its four activity choices to those levels in order. Under 3 years it uses the infant equation EER = 89 × weight − 100 plus an energy-deposition allowance (175 kcal under 3 months, 56 at 3–5 months, 22 at 6–11 months, 20 at 1–2 years). Ages 19 and over return a message. Results are estimates for healthy, normally growing children; follow growth charts and a pediatrician's advice.
How to use
Suppose a 10-year-old boy weighs 32 kg, is 140 cm (1.40 m) tall, and is moderately active (PA 1.26). EER = 88.5 − 61.9 × 10 + 1.26 × (26.7 × 32 + 903 × 1.40) + 25 = 88.5 − 619 + 1.26 × (854.4 + 1,264.2) + 25 = 88.5 − 619 + 2,669.4 + 25 ≈ 2,164 kcal/day. A girl with the same measurements and activity (PA 1.31) gets 135.3 − 308 + 1.31 × (320 + 1,307.6) + 25 ≈ 1,984 kcal/day. Enter age, weight, height, sex and activity level to get the result instantly.
Frequently asked questions
How many calories does a 10-year-old boy need per day?
A 10-year-old boy's daily calorie needs depend on his weight, height, and how active he is. Using the IOM EER equations, a moderately active 10-year-old boy of average size (about 32 kg and 140 cm) needs roughly 2,100–2,200 kcal per day, and a sedentary one about 1,550. This calculator gives a personalized estimate based on his specific measurements. Always consult a pediatrician before making significant changes to a child's diet.
What activity level should I choose for my child in the calorie calculator?
Sedentary means little or no exercise beyond normal daily movement such as walking to school. Light activity covers 1–3 days per week of play or sports. Moderate activity applies to children active 3–5 days per week. Very active is appropriate for children who train or play sport 6–7 days per week or have physically demanding routines. When in doubt, choose the level that best matches a typical week rather than the child's most active day.
Why do boys and girls have different calorie formulas?
The IOM EER equations use different constants for boys and girls because biological differences in muscle mass, fat distribution, and hormones affect basal metabolic rate. Boys generally have a higher proportion of lean muscle mass even during childhood, which burns more calories at rest. These sex-specific coefficients have been validated across large population studies. The difference becomes more pronounced during puberty when hormonal changes accelerate divergence in body composition.