Daily calorie needs (Mifflin–St Jeor).
These calculators use established formulas (such as Mifflin-St Jeor for calorie needs or the Devine formula for ideal weight) to provide general estimates. They're built for a general population and don't account for individual medical conditions, medications, or circumstances. They aren't a substitute for advice from a doctor, registered dietitian, or other qualified healthcare provider — especially for anything related to pregnancy, chronic conditions, or medication dosing.
Uses Mifflin-St Jeor to estimate BMR (calories at rest), then multiplies by an activity factor to estimate TDEE.
Common targets: subtract 250–500 kcal/day for slow loss; add 200–500 for lean gain.
TDEE is an estimate, not a lab-measured number — actual daily burn varies with sleep, stress, and non-exercise movement, so treat the result as a starting point to adjust from based on real-world results over a few weeks.
30-year-old, 175 cm, 70 kg male, moderate activity: BMR 1,649 kcal, TDEE 2,556 kcal. -500 for loss (2,056); +300 for gain (2,856).
Mifflin-St Jeor is the best simple formula for most adults. Katch-McArdle can be better if you know body-fat %.
Every 5–10 lb (2–5 kg) weight change or when activity changes. Body adapts, so numbers drift.
Common causes: overestimated activity, underestimated portions, decreased NEAT (fidgeting). Track intake for a week.
Be conservative — most people overestimate their own activity level. If unsure between two options, pick the lower one and adjust after tracking actual results for two weeks.