Teenagers have higher calorie needs than adults due to active growth and development. This calculator estimates TDEE for teens aged 13-19 using the Mifflin-St Jeor equation, adjusted for the higher energy demands of puberty and physical development.
Last reviewed: September 2026 · How we calculate results · Editorial policy
During puberty and adolescence, the body undergoes rapid physical change. Bone density increases, muscle mass develops, and organ systems mature - all of which require significant energy. This is why teenagers have higher calorie needs per kilogram of bodyweight than most adults.
The Mifflin-St Jeor equation used here calculates BMR from height, weight, age, and sex - then multiplies by an activity factor to estimate TDEE. While originally validated in adults, it provides a reasonable starting estimate for teenagers when used carefully.
Teenage athletes have exceptionally high energy needs - combining the demands of growth with intense physical training. Under-fuelling is common and harmful, leading to fatigue, impaired development, reduced performance, and increased injury risk.
A teenage athlete training daily may need 3,000-3,500+ kcal per day. This should come from whole foods with adequate carbohydrates for fuel, protein for muscle repair, and healthy fats for hormonal health.
BMR = approx. 1,750 kcal
TDEE = 1,750 x 1.725 = approx. 3,019 kcal/day
This is just to maintain weight - growth may require more.