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TDEE calculator

Your maintenance calories from the Mifflin-St Jeor equation — the same math dietitians use, with every step of the calculation shown. Ages 13–17 get the Schofield equation, the adolescent standard, instead. Nothing hidden, nothing gated.

Height
Weight

For ages 13 and up. Ages 13–17 get the Schofield equation — the adolescent BMR standard; adults get Mifflin-St Jeor. The math below says which one ran.

BMR · at rest
1,331
kcal/day
TDEE · maintenance
2,064
kcal/day

The math, step by step

1 · BMR (Mifflin-St Jeor): 10×63.05 + 6.25×165.1 − 5×34 − 161 = 1,331.4

2 · TDEE = 1,331.4 × 1.55 = 2,064 kcal/day

Adults get Mifflin-St Jeor — the adult resting-energy standard. For ages 13–17 this calculator switches to the Schofield equation, the adolescent standard.

Your TDEE at every activity level

  • Sedentary (desk job, little exercise) · ×1.21,598 kcal
  • Light (exercise 1–3×/wk) · ×1.3751,831 kcal
  • Moderate (exercise 3–5×/wk) · ×1.55your pick2,064 kcal
  • Heavy (hard exercise 6–7×/wk) · ×1.7252,297 kcal
  • Athlete (physical job or 2×/day) · ×1.92,530 kcal

Intermediate numbers are shown to a decimal so you can check the arithmetic; final figures are rounded to whole calories. Planning estimates, not clinical prescriptions.

Next step: turn your TDEE into daily protein, carb, and fat targets for losing, maintaining, or gaining — with the safety clamps shown — in the free macro calculator.

How this calculator works

First it estimates your BMR— basal metabolic rate, the calories your body burns at complete rest — with the Mifflin-St Jeor equation (1990), which the Academy of Nutrition and Dietetics' 2005 systematic review found the most reliable resting-energy estimator for healthy adults:

BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age
      + 5 for men · − 161 for women

Mifflin-St Jeor was derived from adult data, so for ages 13–17 the calculator switches to the Schofield equations (1985) — the adolescent standard the WHO adopted, estimated from weight and sex:

BMR = 17.686 × weight (kg) + 658.2  ·  boys 13–17
BMR = 13.384 × weight (kg) + 692.6  ·  girls 13–17

Then it multiplies BMR by a standard activity factor to get your TDEE — total daily energy expenditure, the calories that hold your weight steady:

  • Sedentary — desk job, little exercise · ×1.2
  • Light — exercise 1–3×/week · ×1.375
  • Moderate — exercise 3–5×/week · ×1.55
  • Heavy — hard exercise 6–7×/week · ×1.725
  • Athlete — physical job or 2×/day training · ×1.9

Sources: Mifflin-St Jeor, Am J Clin Nutr 1990 (adult resting-energy equation) · Academy of Nutrition and Dietetics systematic review, J Am Diet Assoc 2005 (why dietitians use it) · Schofield, Hum Nutr Clin Nutr 1985 (adolescent BMR equations, 10–18 band). Planning estimates, not clinical prescriptions.

Common questions

What is TDEE?
Total daily energy expenditure — the calories your body burns in a full day: your resting metabolism (BMR) plus everything you do on top of it. Eat around your TDEE and your weight holds steady; a deficit below it loses weight, a surplus above it gains.
How accurate is the Mifflin-St Jeor equation?
It is the resting-energy equation the Academy of Nutrition and Dietetics found most reliable for healthy adults in its 2005 systematic review, which is why dietitians default to it. It is still an estimate from population data — treat the result as a starting point and adjust from what the scale actually does over a few weeks.
Which activity level should I pick?
Most people overestimate. Count only structured exercise and genuinely physical work: a desk job with no workouts is sedentary (×1.2); 1–3 workouts a week is light (×1.375); 3–5 is moderate (×1.55). Pick the lower bucket when unsure — you can always adjust upward if you are losing weight faster than intended.
Why do 13–17-year-olds get a different equation?
Mifflin-St Jeor was derived and validated on adults, so running it on a teenager would be quietly wrong. For ages 13–17 this calculator uses the Schofield equations — the adolescent standard, adopted by the WHO — which estimate resting energy from weight and sex. The calculation chain always shows which equation your numbers used.
What do I do with my TDEE?
Use it as your maintenance line. For adults 18 and up, our macro calculator runs the next step — adjusting from maintenance at a sustainable pace (a common planning band is 0.25–1% of bodyweight per week) with protein, carb, and fat targets. For 13–17-year-olds the maintenance number itself is the takeaway; we don’t plan deficits or surpluses for anyone under 18.