TDEE Calculator

What is TDEE?

Total Daily Energy Expenditure (TDEE) is an estimate of how many calories you burn per day when exercise is taken into account. It is calculated by first figuring out your Basal Metabolic Rate (BMR), then multiplying that value by an activity multiplier.

Understanding your TDEE is essential for achieving any fitness goal, whether it's weight loss, weight gain, or maintaining your current weight.

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories required to keep your body functioning at rest. BMR is also known as your body's metabolism; therefore, any increase in your metabolic weight will increase your BMR.

The BMR calculation uses the Mifflin-St Jeor equation, which is considered one of the most accurate methods for estimating BMR:

• For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) + 5
• For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) - 161

TDEE Calculation

Once you know your BMR, you can calculate your TDEE by multiplying your BMR by your activity level multiplier:

Activity Level Multipliers:

• Sedentary (little or no exercise): BMR × 1.2
• Light (exercise 1-3 days/week): BMR × 1.375
• Moderate (exercise 3-5 days/week): BMR × 1.55
• Active (exercise 6-7 days/week): BMR × 1.725
• Very Active (hard exercise daily): BMR × 1.9

Weight Management

Once you know your TDEE, you can adjust your calorie intake to meet your goals:

• Weight loss: Weight Loss: Consume 250-500 calories less than your TDEE to lose 0.25-0.5 kg per week. For faster weight loss of 1 kg per week, create a deficit of 1000 calories per day.
• Maintain weight: Weight Maintenance: Consume calories equal to your TDEE to maintain your current weight.
• Weight gain: Weight Gain: Consume 250-500 calories more than your TDEE to gain 0.25-0.5 kg per week. For faster weight gain of 1 kg per week, create a surplus of 1000 calories per day.

Important Notes

• These calculations are estimates and may vary based on individual factors such as genetics, hormones, and medical conditions.
• Extreme calorie deficits or surpluses are not recommended for most people and should only be undertaken under medical supervision.
• For sustainable weight loss or gain, aim for gradual changes (0.25-0.5 kg per week).
• Combine proper nutrition with regular exercise for best results.
• Consult with a healthcare professional or registered dietitian before making significant changes to your diet or exercise routine.

Which BMR equation does this calculator use and why?

Mifflin-St Jeor (1990): BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) + 5 for men, or - 161 for women. The American Dietetic Association compared four major BMR equations against indirect calorimetry in a 2005 review and concluded Mifflin-St Jeor was the most accurate for both normal-weight and obese adults, predicting within 10% of measured BMR in 82% of healthy individuals. The older Harris-Benedict equation (1919, revised 1984) systematically overestimates BMR by 5-10% in modern populations because the original sample was lean adults from a different era. Katch-McArdle is more accurate but requires body-fat percentage as input, which most users don't know. Mifflin-St Jeor strikes the right balance of accuracy and inputs that everyone has.

Why are the activity multipliers (1.2, 1.375, 1.55, 1.725, 1.9) what they are?

These are Physical Activity Levels (PAL) from FAO/WHO/UNU 1985, refined by Frankenfield 2005 and the IOM 2002 dietary reference intakes. They represent total energy expenditure as a multiple of BMR after accounting for activity, including non-exercise activity thermogenesis (fidgeting, posture, occupational movement). 1.2 corresponds to bed-rest or wheelchair-bound. 1.55 represents an office worker who exercises 3-5 days per week. 1.9 is a competitive athlete or heavy manual laborer (construction, farm work). These multipliers are population averages — individual NEAT varies by ±300 kcal/day even at the same activity level, which is one reason TDEE estimates can be off by 200-400 kcal.

How accurate are TDEE calculators in practice?

Less accurate than people assume. A 2019 study by Marra et al. found calculated TDEE was within ±200 kcal of measured TDEE (via doubly labeled water) in only 60% of subjects, with errors up to ±500 kcal in 15% of cases. The main sources of error: 1) BMR variance of ±10% even with the best equations, 2) activity self-reporting unreliability — most people overestimate exercise intensity and underestimate sedentary time, 3) NEAT individual differences of 200-700 kcal/day at the same body weight, 4) adaptive thermogenesis during dieting can reduce BMR by 100-300 kcal beyond predicted. Use the calculator estimate as a starting point, then adjust by 100-200 kcal every 2 weeks based on actual scale results.

What's the safest calorie deficit for weight loss?

A 15-25% deficit below TDEE — typically 300-500 kcal/day for most adults. This produces 0.25-0.5 kg per week of weight loss, the rate the American College of Sports Medicine, NIH, and Mayo Clinic all recommend. Larger deficits (the 1000 kcal extreme weight loss option) work short-term but trigger compensatory metabolic adaptation: thyroid hormones drop 10-15%, leptin falls, NEAT decreases unconsciously, and muscle loss accelerates. The famous Biggest Loser follow-up study showed contestants who lost weight on extreme deficits had BMRs 500 kcal/day below predicted 6 years later. Moderate deficits with strength training preserve muscle, maintain metabolic rate, and are easier to sustain.

What's a realistic muscle-gain calorie surplus?

A 5-15% surplus above TDEE — typically 100-300 kcal/day for natural lifters. This is much smaller than most people expect. The classic Aragon-Schoenfeld 2013 paper on lean bulking found optimal surpluses of 200 kcal/day for intermediate lifters and 100-200 for advanced. Larger surpluses (500-1000 kcal extreme weight gain) result in 60-75% of gained weight being fat, not muscle, because muscle protein synthesis caps at roughly 0.25 kg of new tissue per week in natural trainees. Resistance training stimulus, not raw calories, drives muscle growth — extra calories beyond the body's anabolic ceiling just convert to fat. The mild_weight_gain (250 kcal) option is the practical sweet spot for most users.

Why does my actual TDEE differ from the calculator estimate?

Several factors. First, you may be over- or under-reporting exercise frequency — "moderate" (3-5 days) vs "active" (6-7 days) is a 17% difference in TDEE. Second, your job's activity level matters: a nurse doing 15,000 steps shift-walking burns 300-400 kcal more than someone at a desk, but neither shows up in the activity slider. Third, individual variation in NEAT can be ±500 kcal/day at the same job. Fourth, if you've been dieting recently, adaptive thermogenesis has reduced your BMR below predicted. Fifth, body composition matters: a 75 kg lean athlete burns more than a 75 kg sedentary person because muscle is more metabolically active than fat (Katch-McArdle accounts for this; Mifflin-St Jeor doesn't). Use the calculator as a 2-week starting point and adjust based on real scale data.

Should I recalculate my TDEE as I lose or gain weight?

Yes, every 4-6 weeks or every 5 kg of weight change, whichever comes first. As you lose weight, your BMR drops because there's literally less tissue to maintain — losing 10 kg reduces BMR by about 100 kcal/day according to Mifflin-St Jeor. Additionally, adaptive thermogenesis (metabolic slowdown beyond predicted) adds another 50-150 kcal reduction during sustained dieting. Without recalculating, what was a 500 kcal deficit becomes a 250 kcal deficit and your weight loss stalls. The same works in reverse during a bulk: as you gain muscle and weight, your BMR rises and you need to add calories to keep gaining. Diet breaks (1-2 weeks at maintenance every 6-12 weeks of dieting) help reset hormones and may reduce adaptive thermogenesis.

Is TDEE the same as calories burned?

Yes — TDEE is your total energy expenditure across 24 hours, including everything: BMR (60-70% of TDEE), thermic effect of food or TEF (~10%), exercise activity thermogenesis or EAT (5-15%), and non-exercise activity thermogenesis or NEAT (variable 15-30%). Fitness trackers usually report "calories burned" as just exercise + BMR estimate, missing TEF and underestimating NEAT — they typically read 200-400 kcal/day lower than actual TDEE. The TDEE calculator is more useful for diet planning because it includes everything you actually burn in a day. To create a 500 kcal deficit, you eat TDEE - 500, not TDEE - 500 - exercise.

How do I split my TDEE into protein, carbs, and fat?

Set protein first, then fat, and let carbs fill the rest. Protein is anchored to bodyweight, not total calories, because its job is preserving (or building) lean muscle: aim for about 1.6 g/kg at maintenance, 2.0 g/kg in a cut to protect muscle in a deficit, and 1.8 g/kg in a bulk to support synthesis. A 70 kg lifter cutting therefore eats ~140 g protein (560 kcal). Next, set dietary fat at roughly 25-30% of your target calories — but never below about 0.6 g/kg, since fat is essential for hormone production (testosterone, estrogen) and absorbing fat-soluble vitamins. Whatever calories remain go to carbohydrates (4 kcal/g), your primary training fuel. The macro panel above does this automatically for the goal you pick: choose your target (maintain, cut, or bulk), and it shows grams and percent for each macro from the same Mifflin-St Jeor numbers. Adjust carbs and fat to taste within those bounds — protein and total calories are what matter most for body composition.