Calorie Calculator

How to Use the Calorie Calculator

This calorie calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate formula for estimating daily energy needs. Select your unit system, then enter your age, sex, weight, and height. Choose the activity level that best describes your typical week. The calculator instantly provides your Basal Metabolic Rate (BMR) — the calories your body burns at rest — and your Total Daily Energy Expenditure (TDEE), which includes the energy used during physical activity. You will also see suggested calorie targets for mild and moderate weight loss or weight gain.

Knowing your TDEE is the foundation of any nutrition plan. Whether you want to lose fat, build muscle, or simply maintain your current weight, your daily calorie intake relative to your TDEE determines the outcome. A consistent deficit leads to weight loss, a surplus supports muscle growth, and matching your TDEE maintains your current composition.

Understanding BMR and TDEE

Your Basal Metabolic Rate represents the minimum energy your body requires to sustain vital functions — breathing, circulating blood, regulating temperature, and repairing cells. It typically accounts for 60 to 75 percent of your total daily calorie burn. Your TDEE builds on BMR by adding the thermic effect of food (energy used to digest meals, roughly 10% of intake), non-exercise activity thermogenesis (NEAT, such as walking, fidgeting, and household chores), and deliberate exercise. Together, these components determine how many calories you actually use each day.

Activity Level Multipliers

The activity level you select applies a multiplier to your BMR to estimate TDEE. Sedentary individuals (desk job, minimal exercise) use a factor of 1.2. Light activity (one to three workouts per week) uses 1.375. Moderate activity (three to five sessions) uses 1.55. Active individuals (six to seven days of exercise) use 1.725, and very active people (intense daily training or a physically demanding job) use 1.9. Choosing the right level is critical for accuracy — most people overestimate their activity, so when in doubt, select one level lower.

Calorie Targets for Weight Goals

To lose approximately 0.5 kg (about 1 lb) per week, you need a daily deficit of roughly 500 calories below your TDEE. For a gentler approach, a 250-calorie deficit produces about 0.25 kg of loss per week and is easier to sustain long-term. For weight gain, adding 250 to 500 calories above your TDEE supports muscle growth when combined with resistance training. Extreme deficits below 1,200 calories for women or 1,500 for men can slow metabolism, cause nutrient deficiencies, and should only be undertaken with medical guidance.

Frequently Asked Questions

How many calories do I need per day?

Daily calorie needs vary based on age, sex, weight, height, and activity level. The average adult woman needs approximately 1,600 to 2,400 calories per day, while the average adult man needs approximately 2,000 to 3,000. Use a TDEE calculator to get a personalized estimate.

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic life functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor that accounts for all physical activity throughout the day.

How many calories should I eat to lose weight?

A safe rate of weight loss is 0.5 to 1 kg (1 to 2 lbs) per week, which requires a daily deficit of approximately 500 to 1,000 calories below your TDEE. It is generally not recommended to eat fewer than 1,200 calories per day for women or 1,500 for men without medical supervision.

What is the Mifflin-St Jeor equation?

The Mifflin-St Jeor equation is considered the most accurate formula for estimating BMR. For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5. For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161.

Does exercise increase the number of calories I need?

Yes, physical activity increases your total daily energy expenditure. The more intense and frequent your exercise, the more calories you burn. Activity multipliers range from 1.2 for sedentary individuals to 1.9 for very active people who exercise intensely six or seven days per week.