About This Calculator
Knowing how many calories your body needs each day is one of the most useful tools for managing your weight. This calculator estimates your Total Daily Energy Expenditure (TDEE) — the total number of calories your body burns in a day accounting for your activity level — as well as your Basal Metabolic Rate (BMR), which is the calories your body needs at complete rest.
Results are calculated using the Mifflin-St Jeor equation, which is widely regarded as the most accurate formula for estimating calorie needs in most adults and is recommended by the Academy of Nutrition and Dietetics.
🧮 Calculate Your Daily Calorie Needs
Understanding Your Results
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — the minimum energy needed to keep you alive. It accounts for breathing, circulation, cell production, and temperature regulation. BMR typically accounts for 60–75% of total daily calorie expenditure.
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. This is your maintenance number — eating at this level will keep your weight stable over time. To lose weight, eat below your TDEE; to gain weight, eat above it.
Weight loss and gain targets are based on the widely accepted principle that one pound of body fat contains approximately 3,500 calories. A daily deficit of 500 calories therefore produces approximately one pound of fat loss per week.
Once you know your daily calorie target, use our food search to look up calories in over 350,000 foods, and our free Food Tracker to log your daily intake against your goal.
About the Mifflin-St Jeor Equation
The Mifflin-St Jeor equation was developed in 1990 and has since become the preferred formula for estimating resting metabolic rate among nutrition professionals. Multiple studies have found it more accurate than the older Harris-Benedict equation, particularly for people with obesity.
For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
TDEE is then calculated by multiplying BMR by an activity multiplier ranging from 1.2 (sedentary) to 1.9 (extremely active). The calculator above handles all unit conversions automatically.
❓ Frequently Asked Questions
Daily calorie needs (also called Total Daily Energy Expenditure or TDEE) is the total number of calories your body burns in a day. It includes your basal metabolic rate (calories burned at rest), the thermic effect of food (calories burned digesting), and physical activity.
Eating this many calories maintains your current weight; eating less produces weight loss; eating more produces weight gain.
Most calculators use the Mifflin-St Jeor equation to estimate basal metabolic rate (BMR), then multiply by an activity factor (1.2 for sedentary up to 1.9 for very active).
The Mifflin-St Jeor equation is the most accurate widely-used formula, typically within 10% of measured values. Newer formulas like the Katch-McArdle equation use body fat percentage instead of just weight for slightly improved accuracy in athletic individuals.
Calculator estimates are typically within 10% of actual needs for most people — meaning a 2,500 calorie estimate could be anywhere from 2,250 to 2,750 in reality.
Individual variation in metabolism, activity level estimation, and body composition all contribute to error. Use the calculated number as a starting point, then adjust based on real-world results over 2-4 weeks.
Be honest and slightly conservative — most people overestimate their activity. Sedentary (1.2) means desk job and minimal exercise. Lightly active (1.375) means light exercise 1-3 days per week.
Moderately active (1.55) means moderate exercise 3-5 days per week. Very active (1.725) means hard exercise 6-7 days per week. Extremely active (1.9) is reserved for physical labor jobs or twice-daily training.
Either approach works. Hitting your target daily is simplest and works well for most people. Some prefer weekly averaging — eating slightly less on weekdays and more on weekends, for example.
Your body responds to your average intake over days and weeks, not single days. Either approach produces the same results if total weekly calories are consistent.
Yes. As you lose weight, your body requires fewer calories to maintain that lower weight — both because there's less of you to fuel and because metabolic rate adapts downward slightly.
Recalculate your needs every 10-15 pounds of weight loss to ensure your calorie target remains accurate. Otherwise weight loss can plateau as your old target becomes your new maintenance level.
Men typically have more muscle mass and lower body fat percentage than women of similar weight, and muscle burns more calories at rest than fat.
A 180-pound man and a 180-pound woman of the same age and activity level will have different calorie needs because of this body composition difference — typically 200-400 calories per day. Mifflin-St Jeor and similar formulas account for this difference automatically.
Yes, modestly. Calorie needs decline approximately 1-2% per decade after age 30, driven primarily by loss of muscle mass (sarcopenia) and reduced physical activity.
The actual reduction varies — people who maintain muscle through resistance training and stay active see far less decline. Recalculate your needs every 5-10 years or when activity levels change significantly.
Knowing your daily calorie target is step one. Hitting it daily is what changes your body. Our AI tracker reads your meal description ("chicken bowl with rice and avocado") and instantly logs the calories — no database searching, no scale required. 100% free.
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