How this calculator works
Resting energy (kcal/day) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + sex coefficient. The Mifflin–St Jeor coefficients are +5 for male and −161 for female.
TDEE = resting energy × activity multiplier. Target = TDEE × (1 + adjustment / 100). Targets round once to whole kcal, and the macro handoff uses that same target.
NIDDK describes physical activity levels from about 1.4 (sedentary) to 2.5 (very active), with 1.6 for mostly sitting plus some weekly moderate activity. helsi uses 1.4 and 1.6 as anchors; 1.8, 2.0 and 2.2 are illustrative whole-day assumptions, not validated exercise-frequency categories.
BMR means basal metabolic rate, measured under strict basal conditions. This equation predicts resting energy expenditure (REE), often loosely called BMR online. Neither is your full daily expenditure. Activity is already included in TDEE; do not add the same workout calories again.
Reading your result
Treat the target as an uncertain scenario. Activity selection, individual metabolism and measurement error can change actual needs. The estimate does not predict a date or rate of weight loss.
Illustrative worked example
Illustrative adult: age 30, male coefficient, 175 cm, 70 kg, activity 1.6. REE = 1,648.75 kcal/day; TDEE = 2,638 kcal/day. A −10% scenario gives 2,374 kcal/day after rounding.
Supported inputs & limitations
For generally healthy adults aged 20–78; the original REE sample spanned 19–78. Not for minors, pregnancy, breastfeeding, eating disorders or clinical nutrition. Adjustments range from −20% through +15%. Targets are 1,500–5,000 kcal/day; deficits are disabled below BMI 18.5. These are product boundaries, not universal safe intake limits. Height 120–230 cm; weight 30–300 kg. Accuracy varies with body composition.
Sources & methodology
These primary sources support the method and context. They do not endorse helsi or verify this implementation.