TDEE stands for Total Daily Energy Expenditure. It represents the total calories your body burns in a 24-hour period, including your Basal Metabolic Rate (BMR), physical activity, and the thermic effect of food (digestion). It's your maintenance calorie level — eating at TDEE maintains your current weight.

How accurate is the Mifflin-St Jeor equation?

The Mifflin-St Jeor equation predicts BMR within ±10% for approximately 80% of adults, making it the most accurate widely-used formula. It was developed in 1990 and validated against indirect calorimetry in multiple studies. The Academy of Nutrition and Dietetics recommends it over older formulas like Harris-Benedict.

Should I use current weight or goal weight for TDEE?

Use current body weight for the most accurate estimate of what you burn right now. Then create a deficit or surplus from that number based on your goal. Recalculate as weight changes.

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest just to maintain vital functions — heartbeat, breathing, brain activity, cell repair. TDEE adds the calories from physical activity and digestion. For a moderately active person, TDEE is typically 1.5–1.7× their BMR.

How many calories should I eat to lose weight?

A deficit of 500 calories below TDEE produces approximately 0.5 kg (1 lb) of fat loss per week. A 300-calorie deficit is more conservative but sustainable. Deficits greater than 1000 kcal/day are not recommended without medical supervision, as they risk muscle loss and metabolic adaptation.

How many calories should I eat to gain muscle?

A surplus of 200–500 calories above TDEE supports muscle gain when combined with resistance training. Larger surpluses don't accelerate muscle growth — the body can only synthesize ~0.25 kg of muscle per week under optimal conditions. Excess calories beyond this are stored as fat.

Should I eat back exercise calories?

If you selected an appropriate activity level, exercise is already factored into your TDEE — don't add more. If you used 'Sedentary' but exercise intensely, you can add 50–75% of estimated exercise calories (fitness trackers overestimate). Eating back 100% often erases your deficit.

What activity level should I choose?

Sedentary: Desk job, minimal walking, no exercise. Lightly Active: Desk job + 1–3 light workouts/week. Moderately Active: Active job or 3–5 workouts/week. Very Active: Physical job or 6–7 intense sessions. Extra Active: Athletes training 2×/day or very physical job + exercise. When unsure, choose lower.

How often should I recalculate TDEE?

Recalculate every 4–8 weeks during active weight change, or whenever you lose/gain more than 5 kg. As weight changes, so does BMR. A 10 kg loss reduces TDEE by roughly 200–300 kcal/day. Failure to recalculate is a common cause of weight loss plateaus.

Why do men have higher TDEE than women?

Men typically have more lean muscle mass and less body fat than women of the same weight. Muscle is metabolically active tissue that burns more calories at rest than fat. Additionally, testosterone promotes higher BMR. The Mifflin-St Jeor equation accounts for this with different constants for each sex.

Does metabolism slow with age?

Yes, but less than commonly believed. BMR decreases about 1–2% per decade after age 20, largely due to muscle loss (sarcopenia). The Mifflin-St Jeor equation includes age in its formula. Resistance training can partially offset age-related metabolic decline by maintaining muscle mass.

What is metabolic adaptation?

Metabolic adaptation (or 'adaptive thermogenesis') is the body's response to prolonged calorie restriction. Beyond the expected BMR decrease from weight loss, the body further reduces energy expenditure by 5–15% as a survival mechanism. This is why weight loss often stalls and diet breaks at maintenance can help.

Is 1200 calories too low?

For most adults, yes. 1200 kcal is below the BMR of nearly all adults and makes it difficult to meet micronutrient needs. Very low calorie diets (<1200 for women, <1500 for men) should only be undertaken with medical supervision. Sustainable weight loss rarely requires such extreme restriction.

How does body composition affect TDEE?

Muscle tissue burns more calories at rest than fat tissue — roughly 6 kcal/lb/day vs. 2 kcal/lb/day. Two people of the same weight but different [body compositions](/tools/body-fat-calculator) will have different BMRs. This is why the Katch-McArdle formula (which uses lean body mass) is more accurate for very lean or very obese individuals.

Can I increase my metabolism?

Modestly, yes. Building muscle through resistance training increases BMR. Eating adequate protein (thermic effect is ~25% vs. 5–10% for carbs/fat) slightly raises TDEE. Staying active outside the gym (high NEAT) matters significantly. Crash dieting, however, reduces metabolism — the opposite of what most people want.

What is NEAT and why does it matter?

NEAT (Non-Exercise Activity Thermogenesis) includes all movement that isn't deliberate exercise — walking, standing, fidgeting, household chores. NEAT can vary by 500–2000 kcal/day between individuals and explains why some people seem to 'eat whatever they want' without gaining weight. Increasing NEAT (walking more, taking stairs) can significantly impact TDEE.

Online Medical Tools — TDEE Calculator

Printed on 8/14/2026

For informational purposes only. This is not medical advice.

Nutrition

TDEE Calculator

Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day. This calculator uses the Mifflin-St Jeor equation — considered the gold standard for BMR estimation — combined with validated activity multipliers to provide your personalized daily calorie target for weight loss, maintenance, or muscle gain.

Formula: Mifflin-St Jeor: Male BMR = 10×weight + 6.25×height − 5×age + 5; Female BMR = 10×weight + 6.25×height − 5×age − 161. TDEE = BMR × Activity Multiplier.

Sex

Age

years

Height

Weight

Activity Level

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How It Works

Enter your stats

Input your sex, age, height, and weight. These values determine your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest.

Select your activity level

Choose the option that best matches your typical week. Activity multipliers range from 1.2 (sedentary) to 1.9 (extra active) and account for exercise and daily movement.

Get your TDEE breakdown

View your estimated daily calorie burn, including BMR and activity calories. Use this number to plan your diet for weight loss, maintenance, or muscle gain.

Who Uses the TDEE Calculator

Weight Loss Planning

Dieters & fitness enthusiasts

Calculate maintenance calories, then subtract 300–500 kcal to create a sustainable deficit. TDEE provides the baseline that makes calorie counting effective. Use the [BMI Calculator](/tools/bmi-calculator) to assess your current weight status and the [Ideal Weight Calculator](/tools/ideal-weight) to set realistic goals.

Muscle Building

Bodybuilders & strength athletes

Determine the caloric surplus needed for lean mass gains. Most athletes add 200–500 kcal above TDEE during bulking phases to fuel muscle protein synthesis.

Nutrition Counseling

Dietitians & nutritionists

Establish evidence-based calorie targets for clients. The Mifflin-St Jeor equation is recommended by the Academy of Nutrition and Dietetics as the most accurate for adults.

Endurance Fueling

Runners, cyclists & triathletes

Ensure adequate energy availability to prevent relative energy deficiency in sport (RED-S). Underfueling impairs performance, recovery, and hormonal health.

Plateau Troubleshooting

Anyone stuck at a weight

Recalculate TDEE after weight loss — as you get lighter, calorie needs decrease. Many plateaus occur because people are eating at their new maintenance level. Track progress with the [BMI Calculator](/tools/bmi-calculator) and reassess goals with the [Ideal Weight Calculator](/tools/ideal-weight).

Research & Clinical Studies

Researchers & clinicians

Estimate energy requirements for metabolic studies, weight management trials, and clinical nutrition interventions where indirect calorimetry is not available.

Pro Tips

Start conservative with activity level

Most people overestimate how active they are. If unsure, select one level lower than you think. It's easier to add calories later than to undo overeating.

Don't count exercise twice

If you select 'Very Active', your workouts are already factored in. Don't add extra calories for individual gym sessions — that leads to overestimating needs.

Recalculate every 4–8 weeks

As your weight changes, so does your TDEE. A 10 kg loss can reduce maintenance calories by 200–300 kcal/day. Recalculate regularly to avoid plateaus.

Track for 2–3 weeks before adjusting

Weight fluctuates daily from water, sodium, and digestion. Give any calorie target at least 2–3 weeks before deciding it's too high or too low.

Consider NEAT, not just exercise

Non-exercise activity thermogenesis (walking, fidgeting, standing) can vary by 500+ kcal/day between individuals. A desk job vs. retail job matters as much as gym time.

Use TDEE as a starting point, not gospel

Equations predict averages, not individuals. Your actual metabolism may be 10–15% higher or lower. Real-world results trump calculator estimates every time.

Factor in metabolic adaptation during dieting

Prolonged deficits reduce metabolic rate beyond what weight loss alone predicts. After extended dieting, your true TDEE may be lower than calculated — diet breaks can help.

Separate training days from rest days

Consider eating slightly more on heavy training days and less on rest days. This 'calorie cycling' can improve performance while maintaining weekly targets.

Account for thermic effect of food

Protein has a higher thermic effect (~25%) than carbs (~8%) or fat (~3%). High-protein diets slightly increase actual TDEE beyond calculator estimates. Calculate your optimal protein intake with the [Protein Intake Calculator](/tools/protein-intake).

Combine with macro calculator

Once you have your TDEE, use our [Macro Calculator](/tools/macro-calculator) to split calories into protein, carbs, and fat targets. This ensures balanced nutrition, not just calorie counting.

Common Questions About Your Results

Evidence-Based Methodology

This calculator uses the Mifflin-St Jeor equation (1990), which the Academy of Nutrition and Dietetics identifies as the most accurate predictive equation for estimating resting metabolic rate in non-obese and obese adults. Activity multipliers are based on the original Harris-Benedict activity factors, validated in subsequent metabolic research.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

Your TDEE represents the estimated number of calories your body uses in a 24-hour period. Eating roughly at this level should maintain your current weight over time. To lose weight, a moderate deficit of 300–500 calories below TDEE is generally recommended — this supports a rate of about 0.25–0.5 kg (0.5–1 lb) of fat loss per week. To gain weight or build muscle, eating 300–500 calories above TDEE is a common starting point.

The result also shows your estimated Basal Metabolic Rate (BMR), which is the calorie cost of simply keeping your body alive at rest. The difference between your BMR and TDEE reflects the energy cost of your daily movement, exercise, and the thermic effect of food.

When to Use This Tool

Use this calculator when planning a nutrition strategy for weight management, body recomposition, or athletic performance. It is a helpful starting point before using a [macro calculator](/tools/macro-calculator) to divide your calorie target into protein, carbohydrates, and fat.

TDEE is also useful when working with a dietitian or coach to set initial calorie targets, or when you want to understand why your weight has been changing despite eating a consistent diet — your activity level may have shifted.

Limitations

TDEE calculators rely on self-reported activity levels, which are inherently subjective. Someone who selects "moderately active" may actually fall closer to "lightly active" or "very active" depending on how they define their routine. This is the single largest source of error.

The Mifflin-St Jeor equation estimates BMR within about ±10% for most adults, but accuracy decreases at the extremes — in individuals who are very lean, very obese, elderly, or highly muscular. It does not account for metabolic adaptation (the body's tendency to reduce energy expenditure during prolonged calorie restriction) or individual variation in non-exercise activity thermogenesis (NEAT).

For best results, treat your TDEE as a starting estimate and adjust based on real-world weight trends over 2–3 weeks.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Changelog

April 21, 2026 · trust-baseline
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