TDEE Calculator

Your Total Daily Energy Expenditure is the number of calories you burn in a 24-hour period. It’s not just about the calories you torch during a workout. TDEE is the sum of everything your body does to stay alive, move, and process food.

This calculator provides an estimate, a starting point for understanding your personal energy budget. That number is the key to any weight goal, whether you want to lose, gain, or maintain. A foundational study from 1990 established the Mifflin-St Jeor equation as a reliable method for estimating the largest piece of your TDEE, your basal metabolic rate (PMID: 2305711).

How TDEE Is Calculated

The formula is a two-step process. First, we estimate your Basal Metabolic Rate. This is the energy your body uses at complete rest for basic functions like breathing and circulation. The calculator uses the Mifflin-St Jeor equation for this, which research has shown to be the most reliable predictor for most adults (PMID: 15883556).

The equation differs by sex. For men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. This BMR is then multiplied by an activity factor that represents your daily movement.

These multipliers range from 1.2 (sedentary) to 1.9 (extra active). They are grounded in physiological data. An analysis of 574 people using the gold-standard doubly labeled water method found that the ratio of total energy expenditure to BMR, called physical activity level, ranges from about 1.2 in sedentary individuals to over 4 in elite athletes (PMID: 8641250).

Understanding Your Results

Your result is an estimated calorie number. If you ate exactly that many calories every day, your weight would theoretically stay the same. This is your maintenance level. The Dietary Guidelines for Americans use this same BMR-times-activity model, estimating needs from 1,600–2,400 kcal/day for women and 2,000–3,200 kcal/day for men, depending on activity.

The activity level you choose directly shapes this number. Most people overestimate their activity. A person with a desk job who exercises three times a week is typically “lightly active” (multiplier 1.375), not “moderately active” (1.55). Your non-exercise movement, like fidgeting and walking to your car, called NEAT, can vary by up to 2,000 calories a day between two people of the same size (PMID: 12468415). This variability is why your result is an estimate.

Research on successful weight loss maintainers provides a real-world benchmark. These individuals, who had kept off an average of 26 kg for nearly a decade, maintained a physical activity level of about 1.75. This was significantly higher than the 1.61 level seen in normal-weight controls, showing that sustained higher daily activity is a key driver of long-term success (PMID: 30801984).

When to Use This Calculator

Find your starting point for weight change. To lose weight, you would consume fewer calories than your TDEE. To gain, you would consume more. A typical deficit or surplus is 300-500 calories from this maintenance number.

Plan for weight maintenance. After reaching a goal weight, recalculating your TDEE at your new weight gives you a new maintenance target. This helps prevent the common regain.

Understand your energy budget for athletic training. Athletes and active individuals can use it to ensure they are eating enough to fuel performance and recovery, not just to lose weight.

Compare relative needs. Two people of the same weight can have very different calorie requirements based on height, age, gender, and especially activity. This calculator shows why a one-size-fits-all diet plan doesn’t work.

Limitations

TDEE calculators provide an estimate. Individual results can vary by 10–15% or more from predicted values due to differences in body composition, hormones, and metabolic adaptation. The Mifflin-St Jeor equation was validated primarily in healthy, non-athlete adults aged 19–78. Accuracy may be lower in elite athletes, very elderly individuals, or those with significant medical conditions.

The activity multipliers are broad categories. They cannot capture the precise impact of your unique daily movement, especially the highly variable component of non-exercise activity thermogenesis. Two people who select “moderately active” could have real expenditures hundreds of calories apart.

Metabolic adaptation is a real phenomenon. When you consistently eat in a calorie deficit, your body adapts. Your BMR may decrease slightly, and you may unconsciously move less. This means your actual TDEE on a diet can drift below the calculator’s initial estimate. It’s a moving target.

Tips for Accuracy

Choose your activity multiplier conservatively. Be brutally honest. A person who exercises 3 times per week but sits at a desk all day is typically “lightly active,” not “moderately active.” Most people overestimate.

Use the result as a starting point, not a gospel truth. Monitor your actual weight trend over 2–4 weeks. If you’re eating at your calculated “maintenance” but losing weight, your true TDEE is higher. Adjust your intake by 100–200 kcal/day based on these real results.

Remember that muscle mass burns more calories at rest than fat mass. If your body composition changes through resistance training, your TDEE will increase, even if your scale weight stays the same. The calculator, which only uses total weight, cannot account for this.

Consider the thermic effect of food. Processing the food you eat costs energy, about 8–15% of your TDEE. A higher-protein diet has a slightly higher thermic effect (20-30% of the protein’s calories are used in digestion) compared to fats or carbs, giving a small metabolic edge.

Recalculate periodically. As you lose or gain weight, or as your activity level changes seasonally, your TDEE changes. Re-run the numbers every 5-10 pounds of weight change or with a significant lifestyle shift.

Frequently Asked Questions

What’s the difference between BMR and TDEE? Your Basal Metabolic Rate is the calories you’d burn if you stayed in bed all day. Your Total Daily Energy Expenditure is your BMR plus all the calories you burn from moving, exercising, and digesting food. TDEE is the complete daily total.

How accurate is this TDEE calculator? It provides a scientifically grounded estimate, but individual variation exists. The underlying Mifflin-St Jeor equation predicts resting metabolic rate within 10% of measured values for most people (PMID: 15883556). Your true TDEE depends heavily on your actual daily movement, which is hard to categorize perfectly.

Why did my TDEE number go down when I lost weight? This is normal and expected. A smaller body requires less energy to maintain. Your BMR calculation is based on your current weight, so as that number drops, your estimated energy needs drop proportionally. This is why calorie needs must be adjusted during a weight loss journey.

Can I use this to calculate a calorie deficit for weight loss? Yes. Your calculated TDEE is your estimated maintenance. To lose weight, you would eat fewer calories than this number. A common starting point is a deficit of 300-500 calories per day, which should lead to a loss of about 0.5-1 pound per week, assuming the estimate is accurate for you.

Do I need to eat back calories burned from exercise? It depends on your goal and the calculator setting. If you selected an activity multiplier that already includes your regular exercise, then no, your TDEE estimate already accounts for it. If you selected “sedentary” and then do a hard workout, those extra burned calories would be in addition to your calculated number.

References

Mifflin, M.D., St Jeor, S.T., Hill, L.A., Scott, B.J., Daugherty, S.A., Koh, Y.O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 51(2), 241-247. PMID: 2305711

Frankenfield, D., Roth-Yousey, L., Compher, C. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association, 105(5), 775-789. PMID: 15883556

Black, A.E., Coward, W.A., Cole, T.J., Prentice, A.M. (1996). Human energy expenditure in affluent societies: an analysis of 574 doubly-labelled water measurements. European Journal of Clinical Nutrition, 50(2), 72-92. PMID: 8641250

Levine, J.A. (2002). Non-exercise activity thermogenesis (NEAT). Best Practice & Research Clinical Endocrinology & Metabolism, 16(4), 679-702. PMID: 12468415

Ostendorf, D.M., Caldwell, A.E., Creasy, S.A., et al. (2019). Physical Activity Energy Expenditure and Total Daily Energy Expenditure in Successful Weight Loss Maintainers. Obesity, 27(3), 496-504. PMID: 30801984

U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition.

Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005). National Academies Press.