TDEE Calculator

TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a full day. It includes your Basal Metabolic Rate (BMR), which covers basic life-sustaining functions like breathing and circulation (about 60–70% of TDEE); the Thermic Effect of Food (TEF), which is the energy used to digest and absorb nutrients (about 10%); and Physical Activity Energy Expenditure, which covers all movement from exercise to daily tasks (about 20–30%). TDEE is important because it represents your true daily calorie needs. Eating above your TDEE leads to weight gain, eating below it leads to weight loss, and matching it maintains your current weight. It is the foundation of any evidence-based nutrition plan. A critical but often underappreciated component is NEAT (Non-Exercise Activity Thermogenesis) — the energy expended through all non-exercise movement including fidgeting, standing, walking around your home, and occupational activity. Research by Dr. James Levine at the Mayo Clinic showed that NEAT can vary by up to 2,000 kcal/day between individuals of similar size, making it the single most variable component of TDEE and a major reason why two people with identical BMRs and exercise habits can have vastly different total energy expenditures.

BMR (Basal Metabolic Rate) is the number of calories your body requires at absolute rest — the minimum energy needed to keep your organs functioning, maintain body temperature, and support cellular processes if you were to lie motionless all day. TDEE (Total Daily Energy Expenditure) builds on BMR by adding the calories burned through physical activity and food digestion. In practical terms, BMR is your 'floor' calorie burn, while TDEE is your 'total' calorie burn including movement. For example, a person with a BMR of 1,600 kcal and a moderate activity level (factor 1.55) would have a TDEE of approximately 2,480 kcal. You should base your calorie intake on TDEE, not BMR, because BMR alone does not account for the energy you expend moving through your day. A common and potentially dangerous mistake is eating at or below BMR while exercising, which creates an excessively large deficit that can trigger adaptive thermogenesis, muscle loss, hormonal disruption, and the psychological burnout that leads to diet abandonment and rebound weight gain.

TDEE calculators based on validated equations like Mifflin-St Jeor are generally accurate within ±10–20% for most adults. The largest source of error is typically the self-selected activity level, which people tend to overestimate. Other factors that reduce accuracy include individual genetic variation in metabolic rate (up to ±15%), body composition differences not captured by equations using total body weight, and metabolic adaptation from prolonged dieting. For the best results, treat your calculated TDEE as a starting point. Track your weight for 2–4 weeks while eating at the calculated level, then adjust by 100–200 calories based on actual weight trends. This iterative approach converges on your true TDEE far more reliably than any equation alone. For even greater precision, have your BMR measured via indirect calorimetry (a 15–20 minute breathing test available at many sports medicine clinics for $75–$200), which determines your actual resting oxygen consumption and reduces the BMR estimation error from ±10–20% to approximately ±5%. Doubly labeled water studies, while expensive and impractical for individual use, remain the gold standard for measuring free-living TDEE and are the benchmark against which all estimation methods are validated.

Most people should choose one level lower than they initially think. If you have a desk job and exercise 3–4 times per week for about 45 minutes each session, 'Lightly Active' is typically more accurate than 'Moderately Active.' Here is a practical guide: Sedentary — desk job, no structured exercise, fewer than 5,000 steps per day. Lightly Active — desk job with 1–3 moderate workouts per week, or 5,000–7,500 daily steps. Moderately Active — somewhat active job or 3–5 intense workouts per week, or 7,500–10,000 daily steps. Very Active — physically demanding job or 6–7 intense workouts per week, or 10,000–12,500 daily steps. Extra Active — hard labor job plus daily intense exercise, or 12,500+ daily steps. When in doubt, select the lower option and adjust upward based on actual weight trends over 2–4 weeks. A practical validation method is to use a step counter for one week alongside your food log: if your weight holds steady while eating at your calculated TDEE, you chose correctly; if you gain, your actual TDEE is lower (reduce activity level selection); if you lose, your actual TDEE is higher.

To lose weight, you need to eat fewer calories than your TDEE creates a calorie deficit. A deficit of 500 calories per day below your TDEE produces approximately 0.5 kg (1 lb) of weight loss per week, which is widely considered a safe and sustainable rate. For example, if your TDEE is 2,400 kcal, aim for 1,900 kcal daily. Avoid going below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision. Increase protein intake to 1.6–2.2 g per kg of body weight to preserve muscle mass. Combine your dietary deficit with resistance training to maintain lean tissue and prevent metabolic slowdown. Recalculate your TDEE every 4–6 weeks as your weight decreases, since a lighter body requires fewer calories. Consider incorporating planned diet breaks of 1–2 weeks at maintenance calories every 8–12 weeks of sustained deficit; the MATADOR study showed this intermittent approach produced 47% greater fat loss than continuous dieting over the same total number of deficit weeks, likely due to partial reversal of adaptive thermogenesis during the maintenance periods.

For muscle gain, you need a calorie surplus above your TDEE to provide the extra energy required for muscle protein synthesis. A lean bulk typically involves eating 250–500 calories above TDEE per day, which supports roughly 0.25–0.5 kg of weight gain per week. Consume 1.6–2.2 g of protein per kg of body weight daily, distributed across 4–6 meals. Pair your surplus with a progressive overload resistance training program hitting each muscle group at least twice per week. Monitor weight gain rate — if you are gaining more than 0.5 kg per week, the excess is likely fat, not muscle. Beginners can sometimes build muscle at maintenance calories through body recomposition, but more experienced lifters generally need a deliberate surplus for continued progress. Advanced strategies like calorie cycling — eating a larger surplus (TDEE + 400–600 kcal) on training days and a smaller surplus or maintenance (TDEE + 0–200 kcal) on rest days — can help minimize fat gain during a bulking phase by timing the largest energy and nutrient influx to coincide with the window of greatest muscle protein synthesis activity.

Eating below your BMR is generally not recommended for most people and should only be done under medical supervision. Your BMR represents the minimum energy your body needs to maintain basic physiological functions — breathing, circulation, hormone production, and cell repair. Consuming fewer calories than your BMR can trigger significant metabolic adaptation, where your body slows down non-essential functions to conserve energy. This can lead to muscle loss, reduced thyroid function, hormonal disruptions (including loss of menstrual periods in women), weakened immune function, impaired cognitive performance, and increased fatigue. While medically supervised very-low-calorie diets (VLCDs) below BMR exist for specific clinical situations — typically for severely obese patients — they require careful monitoring and supplementation. The danger of unsupervised sub-BMR eating is that adaptive thermogenesis can become severe and persistent: the Biggest Loser study documented metabolic rates still suppressed by approximately 500 kcal/day below predicted values six years after the competition, suggesting that extreme restriction can cause long-lasting metabolic damage.

You should recalculate your TDEE every 4 to 6 weeks, or whenever there is a significant change in your weight (more than 2–3 kg), activity level, or lifestyle. As you lose weight, your BMR decreases because there is less body mass to maintain, which in turn lowers your TDEE. For example, losing 5 kg might reduce your TDEE by approximately 50–100 kcal per day. Failing to recalculate means your intended calorie deficit gradually shrinks, causing weight loss to plateau — a phenomenon many dieters experience. Similarly, if you increase your exercise frequency or intensity, your TDEE increases and you may need more calories. Life changes like switching from a desk job to a more physical role, pregnancy, or recovering from injury all warrant a TDEE recalculation. Beyond periodic recalculation, maintaining an ongoing weight trend log (recording daily weigh-ins and calculating a 7-day rolling average) provides real-time feedback on whether your current calorie intake is producing the expected results, often revealing the need for adjustment before a formal recalculation would be scheduled.

The Mifflin-St Jeor equation estimates BMR using weight, height, age, and sex. It is considered the most accurate formula for the general population and is endorsed by the American Dietetic Association. It works well for people with average body compositions. The Katch-McArdle equation uses only lean body mass (total weight minus fat mass) to estimate BMR, requiring you to know your body fat percentage. It is more accurate for athletic and lean individuals because it directly accounts for the metabolically active tissue in your body. For someone with 15% body fat, both formulas may give similar results. However, for a muscular athlete at 10% body fat, Katch-McArdle typically gives a higher (and more accurate) BMR, while for an obese individual at 40% body fat, it gives a lower (and more accurate) BMR than Mifflin-St Jeor. If you know your body fat percentage, Katch-McArdle is preferred; otherwise, Mifflin-St Jeor is the best default choice. The Harris-Benedict equation (revised 1984) sits between these two in terms of methodology and tends to overestimate BMR by 5–15% in obese populations, which is why it has been largely supplanted by Mifflin-St Jeor in clinical practice.

Macronutrient ratios should be tailored to your goals, but evidence-based starting points are as follows. For weight loss: 30–35% protein (to preserve muscle), 35–40% carbohydrates (for energy and training performance), and 25–30% fat (for hormonal health and satiety). For muscle gain: 25–30% protein, 45–55% carbohydrates (to fuel intense training and recovery), and 20–25% fat. For maintenance: 25–30% protein, 45–55% carbohydrates, and 20–30% fat. In absolute terms, protein should be 1.6–2.2 g per kg of body weight regardless of goal, fat should not drop below 0.5 g per kg for hormonal health, and the remaining calories come from carbohydrates. For a 2,500 kcal TDEE targeting weight loss with 30% protein, that means 188 g protein, 219 g carbs, and 83 g fat per day. Adjust these ratios based on individual preferences, training demands, and how your body responds over time. It is worth noting that refeed days — planned days at maintenance calories with emphasis on carbohydrates (60–70% of total intake) — can be strategically inserted every 1–2 weeks during a deficit to temporarily boost leptin levels by 20–30%, improve thyroid hormone output, replenish muscle glycogen, and provide a psychological break from restriction that improves long-term adherence.