Calorie Calculator

Formula

Mifflin-St Jeor: men 10W+6.25H−5A+5; women 10W+6.25H−5A−161 (W kg, H cm, A yrs). TDEE = BMR × activity. Target = TDEE + goal.

Macros: protein 4 kcal/g, carbs 4 kcal/g, fat 9 kcal/g. 3,500 kcal ≈ 1 lb.

How it works

Enter age, sex, height, weight, activity, and goal. The engine picks a BMR equation (Mifflin-St Jeor by default, or a lean-mass equation if you know your body-fat percentage), multiplies by an activity factor from sedentary 1.2 to very active 1.9 to get TDEE, then adds your goal offset (−500 for ~1 lb/week loss, +250 for lean gain). Protein, carbs and fat grams split the target by your macro preset.

Assumptions

• Weight-stable BMR equation; illness, medication, and adaptive thermogenesis excluded.
• Activity factor is self-reported; trackers often over-read by 10–20%.
• Goal offsets assume 3,500 kcal per pound; muscle gain needs training, not just surplus.

Default result

With Defaults: 30y male, 175 cm, 70 kg, moderate activity, Mifflin, maintain: BMR 1649 (Mifflin-St Jeor) · TDEE 2556 · target 2556 kcal (Maintain weight)

Worked examples

Weight-loss target

30y male, 175 cm, 70 kg, moderate activity, Mifflin, −500 goal

BMR 1649 (Mifflin-St Jeor) · TDEE 2556 · target 2056 kcal (Weight loss) — Example calculated with this calculator's formula.

Maintenance

30y female, 165 cm, 60 kg, light activity, Mifflin, maintain

BMR 1320 (Mifflin-St Jeor) · TDEE 1815 · target 1815 kcal (Maintain weight) — Example calculated with this calculator's formula.

Frequently asked questions

How many calories should I eat per day?

It depends on age, sex, size, and activity. Adult women typically need 1,600-2,400 kcal/day and men 2,000-3,000. This calculator personalizes your number: BMR (Mifflin-St Jeor or Katch-McArdle) × activity multiplier, adjusted for your goal.

How many calories do I need to lose 1 lb per week?

One pound of body fat stores about 3,500 kcal, so a daily deficit of 500 kcal below your TDEE yields roughly 1 lb/week — through eating less, moving more, or both. For 0.5 lb/week, use a 250 kcal deficit.

What are maintenance calories?

Maintenance equals your TDEE — BMR multiplied by your activity factor. Eating at maintenance keeps your weight stable. Select "Maintain weight" in the calculator and the highlighted row shows your exact number.

Is eating 1,200 calories a day safe?

It can be appropriate for small, sedentary women under supervision, but for most adults it is too low, risking muscle loss, nutrient deficiencies, and metabolic slowdown. Women should stay above 1,200 and men above 1,500 kcal daily unless a physician guides otherwise.