Calorie Calculator
Estimate your daily calorie needs based on age, sex, height, weight, and activity.
Try an example
1,884 kcal/day
About this calculator
What Is a Calorie Calculator?
A calorie calculator estimates how much energy your body needs each day to stay at your current weight, based on your age, sex, height, weight and activity level. Once you know that maintenance figure, you can set a calorie target for losing, maintaining or gaining weight. It is a planning tool, not a prescription — real needs vary from person to person.
How Daily Calorie Needs Are Estimated
The calculation starts with your basal metabolic rate (BMR), the energy you burn at complete rest to keep your heart beating, lungs working and body warm. That number is multiplied by an activity factor to get your total daily energy expenditure (TDEE). The Mifflin–St Jeor equation is one of the most widely used and generally accurate estimates:
- Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
You can see your BMR on its own with the BMR Calculator.
Worked Example
A 30-year-old woman at 165 cm and 65 kg, with a light activity level, has a BMR of about 1,370 kcal/day and a TDEE of about 1,884 kcal/day — the calories she'd need to maintain her current weight. For a mild 0.5 lb/week loss, that's roughly 1,634 kcal/day; for a standard 1 lb/week loss, roughly 1,384 kcal/day.
Choosing an Activity Level
- Sedentary: little or no exercise, desk job.
- Light activity: 15–30 minutes of elevated heart rate most days.
- Moderate activity: exercise 3–5 days a week.
- Intense activity: 45–120 minutes of elevated heart rate activity.
- Very intense: two or more hours a day, or a physically demanding job.
Be honest here — overestimating activity is the most common reason a calorie target does not match real life.
Losing or Gaining Weight
About 3,500 calories correspond to roughly one pound (0.45 kg) of body weight, so a daily deficit of around 500 calories leads to about one pound lost per week. Gaining works the same way in reverse. Slow and steady is easier to maintain: a sensible rate is about 0.5–1 lb (0.25–0.5 kg) per week, and cutting calories too far can cost muscle, energy and nutrients. Most adults should not eat below roughly 1,200 (women) or 1,500 (men) calories a day without medical supervision.
More Than Counting Calories
Food quality matters as much as quantity. Protein helps you feel full and protects muscle during weight loss, fiber keeps digestion on track, and unprocessed foods tend to be more filling per calorie. Sleep, stress and strength training all affect how your body uses energy. Treat the result of this calculator as a starting estimate, track your weight for two to three weeks, and adjust. Check your weight range first with the BMI Calculator.
Worked example
A 30-year-old woman, 165 cm, 65 kg, with light activity (1-3 workouts/week): BMR = 1,370 kcal/day, TDEE = 1,370 × 1.375 = 1,884 kcal/day to maintain her current weight.
Frequently asked questions
What's the difference between BMR and TDEE?
BMR is the calories your body burns at complete rest; TDEE is BMR × an activity multiplier, the number that actually predicts your maintenance calories.
Why does the formula treat men and women differently?
Men and women have somewhat different body compositions on average, so the Mifflin-St Jeor equation adds 5 for men and subtracts 161 for women to correct for it.
How do I lose or gain weight using this number?
Eat below TDEE for weight loss, above it for weight gain — a roughly 500 kcal/day deficit or surplus corresponds to about 0.5 kg (1 lb) per week.
Is this accurate for athletes or very muscular people?
Mifflin-St Jeor is a population average; it can under- or overestimate for very muscular or very lean individuals — treat it as a starting point to adjust from based on real results.
