TDEE & BMR Calculator
Find out how many calories your body burns per day, then get a personalized macro split for fat loss, maintenance, or muscle gain — all in one calculation.
Energy Breakdown
Macro Split 30/40/30
How to Use This TDEE Calculator
Five quick inputs, one personalized calorie and macro target. Here's how each field feeds the calculation.
Choose units
Pick Imperial (lbs/in) or Metric (kg/cm). The Mifflin-St Jeor equation runs in metric units, so imperial inputs are converted automatically.
Enter age, weight, height, sex
These four variables drive the BMR formula. Sex matters because men carry more lean mass at the same weight, raising BMR by 100-200 calories on average.
Pick an activity multiplier
Be honest. Most desk workers are "sedentary" or "light," not "moderate." Pick the lower option if you're unsure — overestimating activity is the #1 cause of stalled weight loss.
Select your goal
Choose Lose Fat (−500 cal), Maintain (TDEE), or Build Muscle (+350 cal). The calculator also switches to a goal-appropriate macro split automatically.
Track and adjust
Follow the target for 2-3 weeks, then weigh yourself under consistent conditions. If you're not moving toward your goal, adjust calories by 100-200 in the relevant direction and re-test.
TDEE in Action: Cutting vs. Bulking
Same person, opposite goals — these cases show how TDEE drives the entire calorie and macro strategy for a cut versus a lean bulk.
Macro Splits Compared
The calculator picks a split automatically based on your goal, but here's how the three common approaches stack up — and when you might want to deviate.
Three macro splits for three goals
| CutBest 40/35/25 | Maintain 30/40/30 | Bulk 30/45/25 |
|---|
Splits are starting points. Adjust by 5% in any direction based on hunger, energy, and 2-3 week weight trend.
Understanding Your Calorie Needs
BMR Is Your Foundation
Your BMR is the energy your body needs just to stay alive — breathing, circulating blood, maintaining temperature, and cellular repair. It accounts for 60-75% of total daily calories. Muscle tissue burns more calories than fat at rest, so increasing muscle mass raises your BMR. This is why strength training is valuable for long-term weight management.
Activity Multiplier
The activity multiplier converts BMR to TDEE. A sedentary person burns 1.2× BMR, while a very active person burns 1.9×. The difference between sedentary and active is 500-700 calories daily — the equivalent of a substantial meal. Regular exercise also elevates metabolism for hours afterward (EPOC effect).
The 500-Calorie Rule
A deficit of 500 calories per day produces approximately one pound of weight loss per week (since one pound of fat equals about 3,500 calories). This is considered a safe and sustainable rate. Larger deficits cause more muscle loss and metabolic slowdown. For most people, a 500-calorie deficit is achievable through a combination of eating less and exercising more.
Metabolic Adaptation
As you lose weight, your TDEE decreases because a smaller body requires fewer calories. After losing 20 pounds, your TDEE may drop by 200-300 calories. This is why weight loss plateaus are normal and expected. Recalculate your TDEE every 10-15 pounds and adjust your calorie intake accordingly.
Understanding Your TDEE in Depth
What Is TDEE and Why It Matters
Total Daily Energy Expenditure (TDEE) represents the complete number of calories your body burns throughout an entire day, encompassing every physiological process and physical activity. Unlike Basal Metabolic Rate (BMR), which measures only resting energy needs, TDEE provides a comprehensive picture of your true calorie requirements. This number is the single most important metric for anyone seeking to change their body composition, as it establishes the baseline from which all weight management strategies are built.
The significance of TDEE lies in its role as the energy balance reference point. When you consume fewer calories than your TDEE, you create a caloric deficit and lose weight. When you eat more than your TDEE, you enter a caloric surplus and gain weight. Eating exactly at your TDEE maintains your current weight. Understanding this fundamental principle eliminates the guesswork from dieting and provides a data-driven approach to reaching your fitness goals.
The Mifflin-St Jeor Equation Explained
The Mifflin-St Jeor equation is widely regarded as the gold standard for estimating BMR in clinical and fitness settings. Developed in 1990 by Dr. Mark Mifflin and colleagues, it was designed to improve upon older formulas like the Harris-Benedict equation, which had become less accurate for modern populations. Research published in the American Journal of Clinical Nutrition found the Mifflin-St Jeor equation to be the most reliable predictor of resting metabolic rate across diverse populations.
The formula accounts for four key variables: weight, height, age, and sex. 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. The sex difference reflects the average disparity in lean body mass between men and women. While no formula is perfect, the Mifflin-St Jeor equation typically estimates BMR within 5-10% of measured values for most people.
How Activity Level Affects Your Calorie Burn
Physical activity is the most variable component of TDEE and the one you have the greatest control over. The activity multiplier system converts your resting metabolic rate into total daily expenditure by accounting for all movement throughout the day. This multiplier ranges from 1.2 for sedentary individuals to 1.9 for extremely active people, representing a difference of over 50% in daily calorie needs between these two extremes.
It's important to understand that "activity level" encompasses far more than structured exercise alone. It includes everything from walking to your car, climbing stairs, doing household chores, and even fidgeting. A person with a desk job who exercises 3-5 times per week typically falls into the moderately active category (1.55 multiplier), while someone with a physically demanding job plus daily exercise may reach the very active level (1.9 multiplier).
NEAT: The Hidden Calorie Burner
Non-Exercise Activity Thermogenesis, or NEAT, refers to the calories burned through all daily activities that aren't formal exercise or sports. This includes walking, standing, typing, cleaning, gardening, shopping, and even subconscious movements like fidgeting and changing posture. Research from the Mayo Clinic has shown that NEAT can vary by as much as 2,000 calories per day between individuals of similar size, making it a surprisingly powerful determinant of TDEE.
What makes NEAT particularly interesting is its role in metabolic adaptation. Studies have found that when people overeat, many unconsciously increase their NEAT — they fidget more, pace, or simply move around more — which helps dissipate excess calories and protects against weight gain. Conversely, when dieting, people often unconsciously reduce their NEAT, burning fewer calories through daily movement and making weight loss more difficult.
Using TDEE for Weight Loss, Gain, or Maintenance
Your TDEE serves as the foundational number for any body composition goal. For weight loss, a moderate deficit of 300-500 calories below TDEE is generally recommended, as this produces sustainable fat loss of 0.5-1 pound per week while minimizing muscle loss and metabolic slowdown. More aggressive deficits of 500-1,000 calories may be appropriate for individuals with higher body fat percentages, but they carry increased risk of muscle loss.
For muscle gain (bulking), a modest surplus of 250-500 calories above TDEE provides the energy needed for muscle growth while minimizing fat accumulation. Gaining weight too quickly — more than 0.5-1 pound per week for most people — typically results in excessive fat gain rather than lean muscle. For maintenance, simply aim to eat at your calculated TDEE, adjusting up or down by 100-200 calories based on whether you're slowly gaining or losing weight over several weeks.
Why Most People Overestimate Their Activity Level
One of the most common mistakes in TDEE calculation is overestimating activity level. A 2019 study in the journal Obesity found that adults typically overestimate their physical activity by 1-2 categories, often believing they're "moderately active" when they're actually "sedentary" or "lightly active." This overestimation leads to inflated TDEE calculations, which is why many people find they're not losing weight despite "eating below their TDEE."
Several factors contribute to this overestimation. People tend to remember their workouts but forget the other 23 hours of the day spent mostly sitting. A 45-minute gym session, while beneficial, only burns roughly 300-500 extra calories — not enough to jump an entire activity category. When in doubt, choose the lower activity category and use your actual weight change over 2-3 weeks to fine-tune your calorie target.
Frequently Asked Questions
How accurate is this TDEE calculator?
This calculator uses the Mifflin-St Jeor equation, the most accurate formula for most adults (within 5-10% of measured metabolic rate). Individual metabolism varies due to genetics, muscle mass, hormones, and other factors. Use the calculated TDEE as a starting point, then adjust based on actual results over 2-3 weeks.
Why do I need more calories than my BMR?
Your BMR only covers basic survival functions. Everything else — walking, talking, working, digesting food, exercising — requires additional calories. Even "sedentary" activities like typing, standing, and fidgeting burn 20% more than BMR. The thermic effect of food (digesting what you eat) accounts for another 10%.
Should I eat back exercise calories?
Most TDEE calculators already account for your average exercise level. If you use the calculator correctly, you do not need to "eat back" specific exercise calories. The 500-calorie deficit from your TDEE already includes your typical workout burn. Eating extra calories labeled as "exercise calories" from fitness trackers often leads to overeating because these devices overestimate calorie burn by 20-90%.
How do I increase my metabolism?
The most effective way to increase BMR is to build muscle through resistance training. Each pound of muscle burns about 6-7 calories per day at rest (versus 2 calories per pound of fat). Building 10 pounds of muscle adds about 50-70 calories to your daily burn. Other metabolism boosters include adequate protein intake, staying hydrated, getting enough sleep, and avoiding extreme calorie restriction.
Is it safe to eat below my BMR?
Consistently eating below BMR is not recommended for extended periods. It can cause nutrient deficiencies, muscle loss, hormonal disruption (especially thyroid and reproductive hormones), fatigue, and metabolic slowdown. Short periods below BMR may be acceptable for aggressive fat loss phases (2-4 weeks), but should be followed by a recovery period at maintenance calories.
How does age affect calorie needs?
BMR decreases approximately 1-2% per decade after age 20, primarily due to loss of muscle mass (sarcopenia) and hormonal changes. A 50-year-old typically burns 200-300 fewer calories per day than they did at 30, even at the same weight. Resistance training and adequate protein (0.7-1g per pound) help preserve metabolic rate.
How are macros calculated for each goal?
This calculator applies goal-specific splits: 40/35/25 (protein/carbs/fat) for cutting, 30/40/30 for maintenance, and 30/45/25 for bulking. Calories per gram: protein 4, carbs 4, fat 9. So at 2,000 calories with a 30/40/30 split, you get 150 g protein, 200 g carbs, and ~67 g fat.
What is NEAT and why does it matter?
NEAT (Non-Exercise Activity Thermogenesis) is the calories burned through daily activities that aren't formal exercise — walking, standing, cleaning, fidgeting, and even typing. NEAT can vary by 2,000+ calories per day between individuals of similar size. Research shows NEAT automatically increases when people overeat (protecting against weight gain) and decreases when dieting (making weight loss harder). Strategies like using a standing desk, taking walking meetings, and walking 10,000 steps daily can add 300-500 calories to your daily burn.
What is cyclical eating and should I try it?
Cyclical eating involves alternating between higher and lower calorie days — for example, eating at maintenance 5 days per week and creating a larger deficit on 2 days. This can help preserve muscle mass and metabolic rate during fat loss by preventing prolonged severe deficits. For bulking, cycling calories (4 days at surplus, 3 days at maintenance) reduces fat gain. Studies show cyclical approaches produce similar fat loss to continuous deficits but with better muscle retention and adherence.
How does exercise timing affect calorie burn?
Exercise boosts metabolism for 12-24 hours post-workout (EPOC effect), with intense resistance training producing a larger EPOC (100-250 extra calories) than steady-state cardio (50-100). Training in a fasted state may slightly increase fat oxidation during the workout, but total daily fat loss is similar to feeding before training. The most effective timing is whatever allows consistent high-intensity training. Post-workout nutrition (20-40g protein within 1-2 hours) enhances muscle protein synthesis.
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References & Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. "A new predictive equation for resting energy expenditure in healthy individuals." American Journal of Clinical Nutrition. 1990;51(2):241-247.
- Academy of Nutrition and Dietetics. Evidence-based practice guidelines for weight management. 2023.
- National Strength and Conditioning Association (NSCA). Essentials of Strength Training and Conditioning — Energy Systems and Body Composition. 5th Edition.
- Frankenfield D, Roth-Yousey L, Compher C. "Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review." Journal of the Academy of Nutrition and Dietetics. 2005;105(5):775-789.
- Levine JA. "Non-exercise activity thermogenesis (NEAT)." Best Practice & Research Clinical Endocrinology & Metabolism. 2002;16(4):679-702.
TDEE calculations use predictive equations with a 10-20% error margin compared to laboratory indirect calorimetry. Individual energy expenditure varies based on genetics, hormones, muscle mass, and metabolic adaptation. Consult a registered dietitian for personalized nutrition planning.