Daily Calorie Calculator
Find out how many calories you burn per day and what to eat to maintain, lose or gain weight. Uses the Mifflin-St Jeor equation — the formula research has found most accurate for estimating calorie needs.
How to use this calculator
- Enter your sex, age, height and weight — the four inputs the formula needs.
- Choose the activity level that honestly matches your average week (most people overestimate).
- Press Calculate to see your maintenance calories plus targets for losing or gaining weight.
- Track your weight for 2–3 weeks at a target; adjust by 100–200 kcal if it's not moving as expected.
Formula used
Mifflin-St Jeor equation, with W = weight (kg), H = height (cm), A = age (years). Daily needs (TDEE) = BMR × activity multiplier (1.2 sedentary → 1.9 extremely active). A deficit of ~500 kcal/day produces roughly 0.5 kg of weight loss per week.
Example calculation
A 30-year-old man, 170 cm, 70 kg, lightly active:
BMR = 10(70) + 6.25(170) − 5(30) + 5 = 1,618 kcal. Daily needs = 1,618 × 1.375 = 2,225 kcal to maintain. To lose ~0.5 kg/week, he'd eat about 1,725 kcal/day.
How do daily calorie needs work?
Your body burns calories constantly — most of them just keeping you alive. That baseline is your BMR (basal metabolic rate), and it typically accounts for 60–70% of everything you burn. Movement, exercise and digestion add the rest, giving your TDEE: total daily energy expenditure.
Weight change is driven by the gap between calories in and calories out over time. Eat consistently below your TDEE and you lose weight; above it and you gain. The calculator gives a well-tested starting estimate — your real number varies with genetics, muscle mass and daily movement, so treat the first few weeks as calibration.
Why use this calculator?
- Get a science-based starting target instead of guessing or copying someone else's diet numbers.
- See maintenance, loss and gain targets side by side so you can pick a realistic pace.
- Recalculate as your weight changes — calorie needs drop as you lose weight, which is why plateaus happen.
Frequently asked questions
How many calories should I eat to lose weight?
Subtract about 500 kcal from your maintenance number for roughly 0.5 kg (1 lb) of loss per week — a sustainable pace for most people. Larger deficits work faster but are harder to sustain and can cost muscle; avoid going below ~1,200–1,500 kcal without medical supervision.
Why is Mifflin-St Jeor used instead of Harris-Benedict?
Validation studies found Mifflin-St Jeor predicts measured resting metabolic rate more accurately than the older Harris-Benedict equation for modern populations, so it's the standard choice today.
Do I eat back the calories I burn exercising?
Your activity multiplier already includes typical exercise, so no — don't add workout calories on top, or you'll double-count. Only adjust for genuinely unusual days like a long hike or race.
Why am I not losing weight at my calculated deficit?
The formula estimates an average; your actual burn may be lower, portion sizes creep, and metabolism adapts slightly in a deficit. Track honestly for two weeks — if weight hasn't moved, reduce intake by 100–200 kcal or add activity, and re-check.