TDEE Calculator

What Is TDEE?

Your TDEE — Total Daily Energy Expenditure — is the number of calories your body burns in a 24-hour period. It's the foundation of any realistic nutrition plan, whether you're trying to lose weight, gain muscle, or maintain where you are. Think of it like your body's daily energy budget. Just as you can't spend money you don't have without consequences, you can't ignore your calorie balance without affecting your body composition.

TDEE isn't a single thing. It's made up of four distinct components that add up to your total daily calorie burn:

Basal Metabolic Rate (BMR) accounts for roughly 60-70% of your TDEE. This is the energy your body uses just to stay alive — breathing, circulating blood, producing new cells, maintaining body temperature. Your brain alone burns about 20% of your total energy. If you lay in bed all day doing absolutely nothing, BMR is what you'd still burn.

Thermic Effect of Food (TEF) contributes about 10% of TDEE. Your body burns calories just by digesting, absorbing, and processing the food you eat. Protein has the highest thermic effect (20-30% of calories consumed), while carbs and fats are lower (5-10%). So eating 100 calories of protein costs your body more energy to process than 100 calories of fat.

Non-Exercise Activity Thermogenesis (NEAT) is the calories you burn from everything that isn't deliberate exercise — walking to your car, fidgeting at your desk, doing laundry, grocery shopping. For many people, NEAT can vary by 300-500 calories per day depending on their job and lifestyle. A desk worker and a nurse doing 12-hour shifts will have dramatically different NEAT.

Exercise Activity Thermogenesis (EAT) is your intentional workouts. This is usually the smallest component for most people, typically 5-15% of TDEE, because even intense exercise sessions only last an hour or two.

Add these four components together and you get your TDEE. And this number — your personal TDEE — is what determines whether you lose weight, gain weight, or maintain. Eat below it consistently and your body taps into stored energy (fat loss). Eat above it and your body stores the excess (weight gain). Eat at it and you maintain.

The TDEE calculator uses the Mifflin-St Jeor equation, the most validated formula for most populations, combined with activity multipliers to estimate your unique number based on your lifestyle.

How to Use This Calculator

Getting your TDEE estimate takes just a few seconds. Enter your age, gender, weight, height, and activity level. The calculator does the math and returns three key numbers: your BMR, your TDEE, and calorie recommendations for cutting or bulking.

The activity level you select is critical. We use the Harris-Benedict activity multipliers:

Most people underestimate their activity level, which is why the calculator's output might be lower than you expect. Be honest. If you work an office job and do a 30-minute workout three times a week, you're "lightly active," not "very active."

Behind the scenes, the calculator uses the Mifflin-St Jeor equation, which we'll dive into below. This equation predicts your Basal Metabolic Rate, and then multiplies it by your activity factor to give you your TDEE.

The results show you three numbers: BMR (your resting calorie burn), TDEE (your total daily burn), and recommendations for a calorie deficit (weight loss), surplus (weight gain), or maintenance.

The Mifflin-St Jeor Equation

The Mifflin-St Jeor equation is a predictive formula published in the American Journal of Clinical Nutrition in 1990. It's become the gold standard because it's been tested on thousands of people and validated repeatedly in research.

Here's how it works:

For men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 5

For women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

Once you have your BMR, multiply it by your activity factor to get your TDEE.

Example: A 30-year-old man, 180 cm tall, weighing 85 kg, moderately active.

• BMR = 10(85) + 6.25(180) − 5(30) − 5 = 850 + 1,125 − 150 − 5 = 1,820 cal
• TDEE = 1,820 × 1.55 = 2,821 calories per day

Why Mifflin-St Jeor over older formulas like Harris-Benedict? Multiple validation studies show Mifflin-St Jeor is roughly 5% more accurate across diverse populations, including people across different ages, body compositions, and ethnic backgrounds. When you're planning nutrition around calorie numbers, that accuracy matters.¹

The equation isn't perfect — individual variation around the predicted TDEE is typically ±200-300 calories — but it's reliable as a starting point. Your actual TDEE depends on factors the formula can't account for: muscle mass, genetics, hormones, medications, and even gut bacteria. That's why the calculator result is a prediction, not a verdict. It's your starting hypothesis, which you'll refine based on real-world results.

¹ Mifflin MD, et al. A new predictive equation for resting energy expenditure. Am J Clin Nutr. 1990;51(2):241-247. Frankenfield D, et al. Comparison of predictive equations for resting metabolic rate. J Am Diet Assoc. 2005.

How to Use TDEE for Weight Loss, Gain, and Maintenance

Now that you have your TDEE, here's how to use it.

For maintenance: Eat approximately at your TDEE. If your calculator shows 2,400 calories, aim for 2,350-2,450 calories per day. You won't stay at exactly 2,400 every day — that's unrealistic — but averaging around that number keeps your weight stable.

For weight loss: Eat 300-500 calories below your TDEE. If your TDEE is 2,400, aim for 1,900-2,100 calories per day. This creates a moderate deficit that supports steady fat loss (about 0.5-1 lb per week) while preserving muscle and keeping you sane. Research suggests that a 500-calorie deficit leads to roughly 1 pound of fat loss per week, though the relationship isn't perfectly linear.² The slower you lose, the better your body composition outcome tends to be.

For weight gain (lean bulk): Eat 250-500 calories above your TDEE. If your TDEE is 2,400, aim for 2,650-2,900 calories per day. This surplus supports muscle growth without excessive fat gain, especially when paired with resistance training.

A common mistake: creating an aggressive deficit of 750+ calories per day. The research on metabolic adaptation is clear — large deficits slow your metabolism, increase hunger hormones, tank your energy, and often lead to muscle loss rather than pure fat loss. It's faster in the short term but worse for long-term results and sustainability. You're more likely to stick with a moderate deficit for months than an aggressive one for weeks.³

Once you know your deficit, dial in your macronutrients. You can use our Macro Calculator to split those calories into protein, carbs, and fats in a way that supports your goals.

If you want to get more granular about your deficit, check out our Calorie Deficit Calculator, which helps you dial in the exact daily intake for your specific weight loss timeline.

² Hall KD. What is the required energy deficit per unit weight loss? Int J Obes. 2008;32(3):573-576.

³ Pontzer H, et al. Daily energy expenditure through the human life course. Science. 2021;373(6556):808-812.

Why Most Online TDEE Calculators Are Inaccurate

Here's the honest truth: most online TDEE calculators, including this one, are estimates with meaningful error ranges.

The activity level problem: You're self-reporting your activity level, and humans are notoriously bad at this. You think you're "moderately active" but you're actually "lightly active." You overestimate how many calories you burn at the gym and underestimate how much you're sitting. One study found that people commonly overestimate daily activity by 10-20%, which translates to a 100-200 calorie error in the final TDEE prediction.

Multipliers are averages: The activity multipliers (1.2, 1.375, 1.55, etc.) are population averages. Individual TDEE can vary ±200-300 calories even within the same activity category. Two people with identical stats but different jobs, metabolic health, or genetics can have meaningfully different TDEEs.

TDEE isn't static: As you lose or gain weight, your TDEE changes. If you lose 20 pounds, your TDEE drops because there's less body mass to maintain. Recalculate every 4-6 weeks if you're actively trying to change your weight.

The reality check: The best approach is to use the calculator as a starting point, then adjust based on actual results. Track your intake and weight for 2-3 weeks. If you aimed for a 2,400-calorie maintenance and your weight doesn't budge, your real TDEE is probably around 2,400. If you're losing weight faster than expected, your TDEE is lower than predicted. If you're not losing weight, your TDEE is higher or your tracking is off.

Here's what that tracking process looks like in practice. Say the calculator gives you a TDEE of 2,400 calories. For the first two weeks, eat as close to 2,400 calories as you can while tracking your weight every morning under consistent conditions—same time, after using the bathroom, before eating. At the end of two weeks, average your daily weigh-ins for week one and week two separately. If both weekly averages are nearly identical (within 0.2 kg), your TDEE is genuinely around 2,400. If week two's average is 0.3 kg lower than week one, you're actually in a slight deficit—your real TDEE might be closer to 2,200-2,300. If week two's average is higher, you're in a surplus.

This two-week calibration beats any calculator because it's based on YOUR body's actual response. The calculator got you in the right neighborhood; the tracking data gives you the exact address. After calibrating, adjust your intake by 100-200 calories and repeat. Within 4-6 weeks, you'll have a far more accurate TDEE than any formula can provide.

This real-world adjustment beats perfect math because it accounts for your individual variation, not just population averages.

When to Consult a Professional

The TDEE calculator is useful for most healthy adults with straightforward goals. But there are scenarios where consulting with a professional is more beneficial than relying on a formula.

Medical conditions affect your metabolic rate and calorie needs. Thyroid disorders, PCOS, diabetes, and metabolic syndrome all change your actual TDEE. Medications like antidepressants and corticosteroids influence both metabolism and appetite. If you have any of these, a registered dietitian can account for them in their assessment.

Extreme body compositions (very high muscle mass or very high body fat) have different metabolic needs than the average person the equation was built on. An elite athlete or someone with obesity may need adjusted predictions. If you're unsure about your body composition, our Body Fat Calculator can help you estimate your fat-to-lean mass ratio.

Bariatric surgery changes your calorie needs in ways formulas don't capture.

Persistent plateaus despite consistent calorie tracking suggest something more complex is happening — hormonal imbalance, adaptation, or tracking error. A professional can dig deeper.

History of eating disorders warrants working with a registered dietitian who specializes in eating disorders and has a trauma-informed approach. Formula-based calorie counting can be harmful in these situations.

If any of these apply, consider working with a registered dietitian or sports nutritionist who can provide a more personalized estimate using indirect calorimetry (measuring your actual metabolic rate) or other tools. It costs more but can be worth it.

Frequently Asked Questions

What is a good TDEE for weight loss?

There's no single "good" TDEE — your TDEE is just a number unique to you. What matters is eating below it consistently. A 300-500 calorie deficit below your personal TDEE is generally sustainable and produces steady results. If your TDEE is 2,200 and you eat 1,700 calories per day, that's a 500-calorie deficit, which research suggests leads to roughly 1 pound of fat loss per week.

How accurate is a TDEE calculator?

TDEE calculators are typically accurate within ±10-20% for most people, which translates to about ±200-400 calories depending on your TDEE. That's why the calculator gives you a number to start with, not a law. You adjust based on real-world results over a few weeks.

Should I eat below my BMR?

No. Your BMR is the minimum calories your body needs just to stay alive. Eating below your BMR for prolonged periods can suppress your metabolism, cause muscle loss, and tank your energy and hormones. If your BMR is 1,400 and your TDEE is 1,800, never eat below 1,400. Instead, create a deficit between BMR and TDEE (eat 1,400-1,700) and increase activity to create a larger deficit.

How often should I recalculate my TDEE?

Recalculate every 4-6 weeks if you're actively losing or gaining weight. As your weight changes, your TDEE changes proportionally. A 20-pound weight loss can lower your TDEE by 200+ calories.

What's the difference between TDEE and BMR?

BMR is your resting metabolic rate — calories burned if you literally don't move. TDEE is BMR plus the calories you burn through activity (NEAT, exercise, digestion). TDEE is always higher than BMR. If your BMR is 1,600 and you're moderately active, your TDEE might be 2,480 (BMR × 1.55).

Does TDEE change with age?

Yes. The Mifflin-St Jeor equation factors in age because metabolic rate gradually declines with age, roughly 2-8% per decade after age 30, primarily because of muscle loss. Staying active and maintaining muscle mass helps offset this decline.

Sources & Medical References

1. Mifflin MD, et al. A new predictive equation for resting energy expenditure. American Journal of Clinical Nutrition. 1990;51(2):241-247. https://doi.org/10.1093/ajcn/51.2.241

2. Frankenfield D, et al. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association. 2005;105(5):775-789. https://doi.org/10.1016/j.jada.2005.02.005

3. Hall KD. What is the required energy deficit per unit weight loss? International Journal of Obesity. 2008;32(3):573-576. https://doi.org/10.1038/sj.ijo.0803720

4. Pontzer H, et al. Daily energy expenditure through the human life course. Science. 2021;373(6556):808-812. https://doi.org/10.1126/science.abe5017