How to Calculate Your TDEE: The Complete Guide to Total Daily Energy Expenditure

The quick answer: Your TDEE (Total Daily Energy Expenditure) is how many calories you burn per day. Calculate it by finding your BMR with the Mifflin-St Jeor equation — (10 x weight in kg) + (6.25 x height in cm) - (5 x age) +/- a constant — then multiply by your activity factor (1.2 to 1.9). A 30-year-old man who is 180 cm, 80 kg, and moderately active has a TDEE of about 2,542 calories.

What Is TDEE and Why Does It Matter?

TDEE stands for Total Daily Energy Expenditure. It is the total number of calories your body burns in a 24-hour period, including everything from breathing and pumping blood to walking, exercising, and digesting food.

Your TDEE is made up of four components:

Most people are surprised to learn that formal exercise accounts for only 5-10% of total daily calorie burn. Your BMR and NEAT — the non-exercise movement throughout your day — are responsible for 75-90% of calories burned.

Understanding your TDEE matters because it is the foundation for every nutritional goal:

• Weight loss: Eat below your TDEE
• Maintenance: Eat at your TDEE
• Weight gain / muscle building: Eat above your TDEE

Without knowing your TDEE, any calorie target is a guess.

The Mifflin-St Jeor Equation: The Most Accurate Formula

Several equations exist for estimating BMR, but the Mifflin-St Jeor equation is the most accurate for most people. A 2005 study published in the Journal of the American Dietetic Association compared multiple prediction equations and found that Mifflin-St Jeor came within 10% of actual measured BMR for 82% of subjects — outperforming the older Harris-Benedict equation and others.

The Formulas

For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5

For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161

These formulas give you your Basal Metabolic Rate — the calories you would burn lying in bed all day doing absolutely nothing. To get your TDEE, you need to account for your activity level.

Activity Multiplier Table

After calculating your BMR, multiply it by the factor that best matches your daily activity level:

Important: Most people overestimate their activity level. If you work a desk job and exercise 3 times a week, you are likely "lightly active" (1.375), not "moderately active" (1.55). Three gym sessions per week does not offset 8+ hours of sitting. When in doubt, choose the lower multiplier.

Step-by-Step TDEE Calculation Example

Let's walk through a complete example.

Profile: Sarah, a 30-year-old woman, 165 cm tall (5'5"), weighing 70 kg (154 lbs), who goes to the gym 3 times per week and works an office job.

Step 1: Calculate BMR

BMR = (10 x 70) + (6.25 x 165) - (5 x 30) - 161

BMR = 700 + 1,031.25 - 150 - 161

BMR = 1,420 calories/day

Step 2: Choose Activity Multiplier

Sarah exercises 3 times a week but sits at a desk all day. She is between "sedentary" and "lightly active." A multiplier of 1.375 (lightly active) is appropriate.

Step 3: Calculate TDEE

TDEE = 1,420 x 1.375

TDEE = 1,953 calories/day

This means Sarah burns approximately 1,953 calories per day. If she eats exactly this amount, her weight will stay stable. If she eats less, she will lose weight. If she eats more, she will gain.

Another Example: Male

Profile: James, 35 years old, 180 cm tall (5'11"), 85 kg (187 lbs), exercises 5 times per week and has a moderately active job.

BMR = (10 x 85) + (6.25 x 180) - (5 x 35) + 5

BMR = 850 + 1,125 - 175 + 5

BMR = 1,805 calories/day

Activity multiplier: 1.55 (moderately active)

TDEE = 1,805 x 1.55 = 2,798 calories/day

TDEE Reference Table by Body Weight and Activity Level

Here is a quick reference showing estimated TDEE for different body weights, assuming average heights and age 30. Use this as a starting point, then refine with the formula above.

How to Use TDEE for Your Goals

For Weight Loss: Subtract 500 Calories

A daily deficit of 500 calories produces approximately 1 lb (0.45 kg) of fat loss per week. This is based on the principle that 1 lb of body fat contains roughly 3,500 calories of stored energy.

Using Sarah's example:

• TDEE: 1,953 calories
• Weight loss target: 1,953 - 500 = 1,453 calories/day
• Expected result: approximately 1 lb lost per week

For faster loss, some people use a 750-calorie deficit (1.5 lbs/week), but deficits larger than 500-750 calories per day tend to increase muscle loss, hunger, and metabolic adaptation. The National Institutes of Health recommends a deficit of 500-750 calories for sustainable weight loss.

Minimum calorie floors: Women should generally not eat fewer than 1,200 calories per day, and men should not go below 1,500 calories per day, without medical supervision. If a 500-calorie deficit would put you below these floors, use a smaller deficit.

For Maintenance: Eat at TDEE

If your goal is to maintain your current weight while improving body composition (losing fat and gaining muscle simultaneously), eat at or very close to your TDEE while prioritizing protein intake (1.6-2.2g per kg of body weight) and resistance training.

For Weight Gain / Muscle Building: Add 300-500 Calories

A surplus of 300-500 calories per day supports muscle growth while minimizing excess fat gain. A 2019 study in the Journal of the International Society of Sports Nutrition found that a surplus of 350-500 calories combined with resistance training maximizes the rate of lean mass gain.

Using James's example:

• TDEE: 2,798 calories
• Muscle gain target: 2,798 + 400 = 3,198 calories/day
• Expected result: approximately 0.5-1 lb of muscle gain per month (alongside some fat gain)

Why Online Calculators Are Just Estimates

Every TDEE calculator — including the formulas above — provides an estimate, not a measurement. Here is why:

Individual metabolic variation. Two people with the same height, weight, age, and activity level can have BMRs that differ by 200-300 calories due to differences in muscle mass, genetics, gut microbiome, thyroid function, and hormonal profiles.

Activity level is subjective. The activity multipliers are broad categories. "Moderately active" could mean anything from a brisk 30-minute walk five times a week to intense CrossFit sessions. The difference could be 200-400 calories.

NEAT is hard to measure. Non-exercise activity thermogenesis varies dramatically between people. A fidgety person with a standing desk can burn 300-500 more calories per day than a sedentary person of the same size, according to research by Dr. James Levine at the Mayo Clinic.

Metabolic adaptation. When you diet, your body gradually reduces its energy expenditure through smaller movements, lower body temperature, and hormonal shifts. A TDEE calculated at the start of a diet may be 10-15% too high after several months of dieting.

This does not mean calculators are useless. They provide a solid starting point — typically within 10-15% of your true TDEE. But you should treat the result as a hypothesis to test, not a fact to follow blindly.

How to Calibrate Your TDEE With Real-World Tracking

The most accurate way to determine your TDEE is to track your intake and weight over 2-4 weeks and let the data tell you. Here is the protocol:

Week 1-2: Gather Data

1. Weigh yourself daily first thing in the morning, after using the bathroom, before eating or drinking. Record every weigh-in.
2. Track your calorie intake accurately using a food scale and a tracking app. Be meticulous — include every oil, sauce, drink, and snack.
3. Calculate your daily average weight for each week by adding all 7 weigh-ins and dividing by 7. This smooths out daily fluctuations from water, sodium, and digestion.

Week 3-4: Analyze

4. Compare weekly averages. If your average weight dropped by 0.5 lbs from week 1 to week 2, you were in a deficit of approximately 250 calories per day (0.5 lbs x 3,500 / 7 days).
5. Back-calculate your TDEE. If you averaged 2,000 calories/day and lost 0.5 lbs/week, your TDEE is approximately 2,000 + 250 = 2,250 calories.

Example Calibration

Sarah starts eating 1,950 calories per day (her calculated TDEE) and tracks for 2 weeks:

• Week 1 average weight: 70.0 kg
• Week 2 average weight: 69.8 kg
• Change: -0.2 kg (about 0.44 lbs)

She lost roughly 0.44 lbs in one week while eating 1,950 calories. This means she was in a deficit of about 220 calories/day, so her actual TDEE is closer to 2,170 calories — somewhat higher than the formula estimated.

This calibration method requires patience but gives you a personalized TDEE far more accurate than any formula. Meal planning apps like Mealift can simplify this process by pre-calculating the calories in your planned meals, so you know exactly what you are eating without manual logging every day.

When to Recalculate Your TDEE

Your TDEE is not a fixed number. Recalculate in these situations:

• Every 5-10 lbs of weight change. For every 10 lbs lost, your TDEE decreases by roughly 70-100 calories because your smaller body requires less energy.
• Major changes in activity level. Starting or stopping an exercise program, changing jobs from sedentary to active (or vice versa), or recovering from an injury.
• Age milestones. BMR decreases by about 1-2% per decade after age 20, primarily due to loss of lean muscle mass.
• After a long dieting phase. Metabolic adaptation means your TDEE after 3-6 months of dieting may be 10-15% lower than predicted. A maintenance phase (eating at TDEE for 2-4 weeks) can help reverse some of this adaptation.

Frequently Asked Questions

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep your organs functioning. TDEE (Total Daily Energy Expenditure) is your BMR plus all additional calories burned through movement, exercise, and digestion. TDEE is always higher than BMR. For most people, TDEE is 1.2 to 1.9 times their BMR, depending on activity level.

Which TDEE formula is the most accurate?

The Mifflin-St Jeor equation is considered the most accurate for the general population. A 2005 validation study found it predicted BMR within 10% for 82% of participants. The older Harris-Benedict equation (from 1919) tends to overestimate by 5-15%. The Katch-McArdle formula can be more accurate if you know your body fat percentage, as it accounts for lean body mass directly.

How many calories should I eat below my TDEE to lose weight?

A deficit of 500 calories per day is the standard recommendation, producing approximately 1 lb of fat loss per week. Larger deficits (750-1,000 calories) produce faster weight loss but increase the risk of muscle loss, nutrient deficiencies, and metabolic adaptation. Never go below 1,200 calories (women) or 1,500 calories (men) without medical supervision.

Why am I not losing weight even though I am eating below my TDEE?

The most common reason is inaccurate calorie tracking. Studies show that most people underestimate their intake by 30-50%. Other possibilities include water retention masking fat loss (especially in the first 1-2 weeks or around menstrual cycles), metabolic adaptation from prolonged dieting, or an incorrectly estimated activity multiplier. Track meticulously for 2 weeks and compare weekly average weights before concluding that your TDEE is wrong.

Does my TDEE change on rest days?

Yes, but less than most people think. Your BMR (60-70% of TDEE) stays the same every day. On rest days, you miss out on EAT (exercise calories), which is typically only 200-400 calories for a standard gym session. Some people eat slightly less on rest days (100-200 fewer calories), but for simplicity, eating the same amount every day and using a weekly average works just as well.

Can I increase my TDEE?

Yes. The most effective way to increase your TDEE is to build muscle through resistance training, since muscle tissue burns more calories at rest than fat tissue — roughly 6 calories per pound of muscle per day versus 2 calories per pound of fat. Increasing your NEAT (walking more, taking stairs, standing desk) can also add 200-500 calories per day. These changes compound over time.

Is TDEE the same as "calories burned" on my fitness tracker?

Not exactly. Fitness trackers estimate total daily calories burned, which is conceptually the same as TDEE, but the accuracy varies. A 2019 study in the Journal of Personalized Medicine found that popular wrist-worn trackers overestimated calorie burn by 28-93% during exercise. Use tracker data as a general trend indicator, not an exact number.

How does age affect TDEE?

TDEE decreases with age, primarily because people tend to lose muscle mass and become less active as they get older. The decline is approximately 1-2% per decade after age 20. However, this decline is not inevitable — people who maintain muscle mass through resistance training and stay physically active can largely offset the age-related decrease in TDEE.