Calculate Your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE)
Use our complete metabolic calculator to discover how many calories your body burns daily and how to distribute your macronutrients (protein, carbs, and fats) to achieve your goals: lose fat, gain muscle mass, or maintain weight.
How Does the Metabolic Calculator Work?
Our calculator uses scientifically validated formulas to estimate your daily caloric needs based on personal data such as age, weight, height, gender, body fat percentage, and activity level.
The calculation is done in two main steps:
- Basal Metabolic Rate (BMR): The minimum amount of energy your body needs to maintain vital functions at rest
- Total Daily Energy Expenditure (TDEE): Your total caloric expenditure including physical activities and exercise
Formulas Used
Our calculator uses the Mifflin-St Jeor equation, considered one of the most accurate for calculating BMR in adults:
For men:
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
For women:
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
When body fat percentage is known, we use the Katch-McArdle formula, which considers lean body mass:
BMR = 370 + (21.6 × lean mass in kg)
Understanding Your Results
After calculating, you’ll receive:
- BMR (Basal Metabolic Rate): Calories burned at complete rest
- TDEE (Total Daily Energy Expenditure): Total calories burned including all activities
- Daily Calorie Goal: Adjusted calories based on your objective (cutting, maintenance, or bulking)
- Macronutrient Distribution: Grams of protein, carbohydrates, and fats
- Per-Meal Breakdown: Macro distribution across your daily meals
How to Interpret the Numbers
Example results:
- A 30-year-old man, 5’11” (180cm), 176 lbs (80kg) → BMR ~1,850 kcal
- A 25-year-old woman, 5’5″ (165cm), 132 lbs (60kg) → BMR ~1,400 kcal
Your TDEE will always be higher than your BMR, as it includes energy spent on exercise, digestion, and daily activities.
How to Use the Calculator to Lose Fat
To lose fat healthily and sustainably, you need a moderate caloric deficit – consuming fewer calories than you burn.
Recommended weekly weight loss:
- Moderate: 0.5-1 lb (0.25-0.5 kg) per week → 250-500 kcal deficit
- Aggressive: 1-1.5 lbs (0.5-0.7 kg) per week → 500-750 kcal deficit
Important Tips for Fat Loss
✅ Prioritize lean proteins to preserve muscle mass
✅ Maintain adequate hydration (2-3 liters daily)
✅ Include strength training to prevent muscle loss
✅ Avoid extreme deficits that compromise metabolism
✅ Monitor weekly progress and adjust as needed
Remember: Excessive deficits can cause fatigue, muscle loss, and metabolic slowdown. Sustainable fat loss is gradual and consistent.
How to Use the Calculator to Gain Muscle Mass
For muscle hypertrophy, you need a controlled caloric surplus – consuming more calories than you burn to provide energy for protein synthesis and muscle growth.
Recommended weekly weight gain:
- Lean bulk: 0.5-1 lb (0.25-0.5 kg) per week → 250-500 kcal surplus
- Aggressive bulk: 1-1.5 lbs (0.5-0.7 kg) per week → 500-750 kcal surplus
Steps to Calculate Your Bulking Calories
- Calculate your BMR using our calculator
- Multiply by your activity factor to get TDEE
- Add 300-500 kcal to create a controlled surplus
- Distribute macros with emphasis on protein (1.6-2.2 g/kg)
Essential supplements for muscle gain: Whey Protein, Creatine, BCAAs, and Multivitamins.
Difference Between BMR and TDEE
Many people confuse BMR with total daily caloric expenditure. Here’s the distinction:
BMR (Basal Metabolic Rate)
The energy your body burns at complete rest just to keep you alive:
- Heart beating
- Breathing
- Cellular functions
- Temperature regulation
TDEE (Total Daily Energy Expenditure)
Your total daily energy expenditure, which includes:
- BMR – Base metabolism (~60-70% of TDEE)
- NEAT (Non-Exercise Activity Thermogenesis) – Daily activities like walking, cleaning, working (~15-30%)
- EAT (Exercise Activity Thermogenesis) – Planned exercise like gym, running (~5-10%)
- TEF (Thermic Effect of Food) – Energy to digest food (~10%)
Your daily caloric intake should be based on TDEE, not BMR.
Factors That Influence Your Metabolic Rate
Your metabolism isn’t static – several factors affect how many calories you burn:
Age
After 20, metabolism naturally decreases 2-3% per decade, mainly due to muscle loss.
Gender
Men typically have 5-10% higher metabolism due to greater muscle mass and less body fat.
Body Composition
Muscle is metabolically active – it burns more calories at rest than fat. This is why strength training is crucial for maintaining a healthy metabolism.
Genetics
Some people naturally have faster or slower metabolisms due to genetic factors.
Hormones
Thyroid hormones, testosterone, cortisol, and insulin directly affect metabolic rate.
Sleep Quality
Poor sleep disrupts metabolism-regulating hormones like leptin and ghrelin, potentially lowering BMR by 5-20%.
Temperature
Cold environments increase caloric expenditure as the body works to maintain core temperature.
Health Conditions That Affect Metabolism
Certain medical conditions can significantly impact your basal metabolic rate:
Hypothyroidism: Underactive thyroid slows metabolism, causing fatigue and weight gain
Hyperthyroidism: Overactive thyroid accelerates metabolism, causing rapid weight loss and anxiety
Diabetes: Can affect glucose metabolism and overall energy expenditure
PCOS: Polycystic Ovary Syndrome can slow metabolism in women
Medications: Antidepressants, beta-blockers, and corticosteroids may alter metabolic rate
If you experience unexplained weight changes, fatigue, or other symptoms, consult a healthcare professional.
Tips to Boost Your Basal Metabolic Rate
Want to increase the calories you burn at rest? Try these evidence-based strategies:
1. Build Muscle Through Strength Training
Muscle tissue burns more calories than fat, even at rest. Regular resistance training is the most effective way to increase long-term metabolic rate.
2. Eat Enough Protein
Protein has the highest thermic effect of all macronutrients (20-30%), meaning your body burns more calories digesting it.
Recommended: 0.7-1g per lb of body weight (1.6-2.2g per kg)
3. Stay Active Throughout the Day (NEAT)
Small movements add up: take stairs, walk during calls, stand while working, park farther away.
4. Get Quality Sleep
Aim for 7-9 hours nightly. Poor sleep reduces metabolism and increases hunger hormones.
5. Stay Hydrated
Water is essential for metabolic processes. Studies show drinking cold water may temporarily boost metabolism.
6. Try High-Intensity Interval Training (HIIT)
HIIT creates an “afterburn effect” (EPOC) where you continue burning calories post-workout.
7. Don’t Skip Meals
Regular eating maintains metabolic activity. Extreme caloric restriction can slow metabolism.
Supplements That Support Metabolism
While no supplement replaces proper diet and training, these can support your metabolic goals:
Caffeine: Stimulates nervous system, increases energy expenditure and fat oxidation
Whey Protein: Preserves muscle mass (the primary driver of metabolic rate) and has high thermic effect
Creatine: Improves workout performance, leading to greater muscle gain and higher metabolism
Omega-3: Supports hormone regulation and reduces inflammation affecting metabolism
Green Tea Extract: Contains catechins that may modestly increase fat oxidation
Thermogenics: Combinations of caffeine, capsaicin, and other compounds designed to boost calorie burning
Always consult a healthcare provider before starting supplementation, especially if you have health conditions.
Common Mistakes When Calculating Calories
Avoid these errors that can sabotage your results:
❌ Underestimating portion sizes – Use a food scale for accuracy
❌ Not tracking consistently – Weekend binges can erase weekly deficits
❌ Forgetting cooking oils and condiments – They add significant calories
❌ Overestimating exercise calories burned – Fitness trackers often overestimate
❌ Eating back all exercise calories – This can eliminate your deficit
❌ Not adjusting as you lose/gain weight – Recalculate every 10-15 lbs lost/gained
❌ Being unrealistic about activity levels – Most people are less active than they think
Macronutrient Distribution Guide
Once you know your calories, here’s how to distribute your macros:
Protein (4 calories per gram)
Purpose: Muscle building, repair, satiety
Recommendations:
- Fat loss: 1-1.2g per lb (2.2-2.6g per kg)
- Maintenance: 0.8-1g per lb (1.8-2.2g per kg)
- Muscle gain: 0.7-1g per lb (1.6-2.2g per kg)
Fats (9 calories per gram)
Purpose: Hormone production, vitamin absorption, satiety
Recommendations:
- 20-35% of total calories
- Or 0.3-0.5g per lb of body weight (0.7-1.1g per kg)
- Prioritize healthy fats: avocado, nuts, olive oil, fatty fish
Carbohydrates (4 calories per gram)
Purpose: Energy for workouts and daily activity
Recommendations:
- Fill remaining calories after protein and fat
- Active individuals/bulking: Higher carbs (40-60% of calories)
- Sedentary/cutting: Moderate carbs (20-40% of calories)
Tracking Your Progress
Using the calculator is just the beginning. Success requires monitoring:
What to Track:
- ✅ Body weight (weekly average, not daily)
- ✅ Body measurements (waist, hips, arms, thighs)
- ✅ Progress photos (weekly, same lighting/pose)
- ✅ Gym performance (strength, endurance)
- ✅ Energy levels and mood
- ✅ Hunger and satiety
When to Adjust: If weight hasn’t changed in 2-3 weeks:
- Fat loss: Reduce calories by 100-200 or increase activity
- Muscle gain: Increase calories by 100-200
Recommended Apps:
- MyFitnessPal
- Cronometer
- FatSecret
- MacroFactor
Frequently Asked Questions
Is this calculator accurate?
Our calculator provides scientifically-based estimates. However, individual metabolism varies due to genetics, hormones, medications, and other factors. Use results as a starting point and adjust based on real-world progress.
Do I really need to count calories?
While not everyone needs to count calories forever, tracking initially helps you understand portion sizes and food composition. It’s especially important when you have specific body composition goals.
What if I don’t know my body fat percentage?
No problem! The calculator works without it using the standard Mifflin-St Jeor formula. However, if you can estimate your body fat through calipers, DEXA scan, or visual comparison, you’ll get slightly more accurate results.
Should I eat the same calories every day?
You can vary calories slightly day-to-day (higher on training days, lower on rest days) as long as your weekly average matches your goal. This is called calorie cycling.
How often should I recalculate?
Recalculate every 10-15 lbs (5-7 kg) of weight change, or if your activity level significantly changes. Your caloric needs decrease as you lose weight and increase as you gain.
Can I lose fat and gain muscle simultaneously?
This is challenging but possible for beginners, people returning from a break, or those with higher body fat. Most people see better results focusing on one goal at a time.
What if the calculator says to eat very low calories?
Never eat below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision. Extremely low calories can harm metabolism, muscle mass, and health. Consider increasing activity instead of drastically cutting calories.
Scientific References
This calculator is based on peer-reviewed research:
- Mifflin MD, et al. “A new predictive equation for resting energy expenditure in healthy individuals.” Am J Clin Nutr. 1990;51(2):241-7.
- Katch FI, McArdle WD. “Prediction of body density from simple anthropometric measurements in college-age men and women.” Hum Biol. 1973;45(3):445-55.
- Heymsfield SB, et al. “Energy expenditure during continuous and discontinuous exercise in obesity.” Am J Clin Nutr. 2012;95(4):791-9.
- Phillips SM, Van Loon LJC. “Dietary protein for athletes: from requirements to optimum adaptation.” J Sports Sci. 2011;29(S1):S29-S38.
Disclaimer
This calculator provides estimates based on population averages and should not replace professional medical or nutritional advice. Individual results may vary based on genetics, health conditions, medications, and lifestyle factors.
Before making significant dietary changes or starting an exercise program, especially if you have health conditions or take medications, consult with a healthcare provider or registered dietitian.
The information provided is for educational purposes and should be used as a general guide to help you understand your approximate caloric needs.