TDEE & BMR Calculator
Calculate your daily calorie needs for weight loss, maintenance, or muscle gain.
Enter your age, height, weight, and activity level, then click "Calculate" to see your BMR, TDEE, and personalized calorie targets.
What Is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day. It includes three components: your Basal Metabolic Rate (BMR — calories burned at rest), the thermic effect of food (TEF — calories burned digesting food), and your physical activity (exercise and non-exercise movement). TDEE is your "maintenance calories" — eating this amount keeps your weight stable.
What Is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body needs at complete rest to perform basic life-sustaining functions: breathing, circulation, cell production, nutrient processing, and temperature regulation. BMR accounts for 60-75% of your TDEE and is determined primarily by your age, sex, weight, height, and body composition. Muscle tissue burns more calories at rest than fat tissue, which is why people with higher muscle mass have higher BMRs.
How TDEE Is Calculated
This calculator uses the Mifflin-St Jeor equation, the most accurate BMR formula for the general population (within ±10% for most adults):
- Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Then we multiply your BMR by an activity factor to estimate your total daily energy expenditure:
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | BMR × 1.2 | Desk job, little or no exercise |
| Lightly Active | BMR × 1.375 | Light exercise 1-3 days/week |
| Moderately Active | BMR × 1.55 | Moderate exercise 3-5 days/week |
| Very Active | BMR × 1.725 | Hard exercise 6-7 days/week |
| Extremely Active | BMR × 1.9 | Athlete, physical job, training twice daily |
Calorie Targets Explained
- Weight Loss (TDEE − 500) — A 500-calorie daily deficit typically results in 0.5 kg (1 lb) of weight loss per week. This is the safest and most sustainable rate for most people. Larger deficits risk muscle loss, metabolic slowdown, and nutritional deficiencies. Never eat below your BMR without medical supervision.
- Maintenance (TDEE) — Your exact maintenance level. Eating at this level keeps your weight stable. Recalculate if your weight or activity level changes significantly.
- Muscle Gain (TDEE + 300) — A moderate surplus supports muscle growth with minimal fat gain. Pair with adequate protein (1.6-2.2 g per kg of body weight) and progressive strength training for best results.
BMR vs. TDEE: What's the Difference?
Think of BMR as the minimum your body needs to survive (if you stayed in bed all day), and TDEE as what you actually burn (with movement, exercise, and daily life). BMR is the foundation (~60-75% of TDEE). The remaining 25-40% comes from activity and digestion. A sedentary person might have a TDEE only 20% above their BMR, while an athlete could have a TDEE 90% above their BMR.
Factors That Affect Your TDEE
- Muscle mass — Muscle burns 3x more calories at rest than fat. Adding 2 kg of muscle increases BMR by approximately 100 calories per day.
- Age — BMR decreases by approximately 1-2% per decade after age 20, primarily due to muscle loss. Strength training can slow or reverse this decline.
- Genetics — Some people naturally have faster or slower metabolisms. This accounts for about 5-10% variation between individuals of the same size and age.
- Hormones — Thyroid hormones, sex hormones, and cortisol all influence metabolic rate. Medical conditions like hypothyroidism can significantly lower BMR.
- Diet history — Chronic calorie restriction can lower BMR by 10-20% through metabolic adaptation. This is why reverse dieting is sometimes needed after extended dieting.
Frequently Asked Questions
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total calories your body burns per day — from basic life functions, daily movement, exercise, and digestion. It's your maintenance calorie level.
What is BMR?
BMR (Basal Metabolic Rate) is the calories your body needs at complete rest just to stay alive. It accounts for 60-75% of your TDEE and is the baseline for all calorie calculations.
How many calories should I eat to lose weight?
A 300-500 calorie deficit below your TDEE is safe and sustainable. This leads to 0.5-1 kg (1-2 lbs) of weight loss per week. Don't eat below your BMR without medical advice.
How many calories should I eat to gain muscle?
A 300-500 calorie surplus above your TDEE supports muscle growth. Combine with adequate protein (1.6-2.2 g/kg body weight) and strength training for optimal results.
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation (1990) is the most accurate BMR formula for the general population. It replaced the older Harris-Benedict equation (1919) and is recommended by the Academy of Nutrition and Dietetics.
Is my BMR the same as my TDEE?
No — BMR is a subset of TDEE. BMR = calories for survival at rest. TDEE = BMR + activity + digestion. Most people's TDEE is 20-50% higher than their BMR, depending on activity level.
Sources: Academy of Nutrition and Dietetics, National Institutes of Health (NIH), American Council on Exercise (ACE), Journal of the Academy of Nutrition and Dietetics (Mifflin-St Jeor study, 1990). Individual metabolism varies — consult a healthcare professional for personalized advice.