Keto. Paleo. Carnivore. Vegan. Intermittent fasting.

Everyone’s arguing about the “best” diet.

Here’s what nobody tells you: it doesn’t matter.

What matters is one number. Your TDEE.

What Is TDEE?

TDEE = Total Daily Energy Expenditure

It’s the total number of calories you burn in a day. Everything included:

  • Breathing
  • Thinking
  • Walking
  • Digesting
  • Existing

For most people, it’s somewhere between 1,800 and 3,000 calories.

If you eat exactly your TDEE, your weight stays the same.

Why It Matters

Here’s the only rule of weight loss that actually works:

  • Eat less than your TDEE = lose weight
  • Eat more than your TDEE = gain weight
  • Eat at your TDEE = maintain weight

That’s it. That’s the whole thing.

Keto works because it makes you eat fewer calories. So does fasting. So does vegan. The method doesn’t matter. The math does.

The Components of TDEE

1. BMR (Basal Metabolic Rate) — 60-70%

Calories burned just existing. If you lay in bed all day, this is what you’d burn.

Includes: heart beating, lungs breathing, brain thinking, cells regenerating.

2. TEF (Thermic Effect of Food) — 10%

Calories burned digesting food.

Protein = highest TEF (~25%) Carbs = medium (~10%) Fat = lowest (~3%)

3. NEAT (Non-Exercise Activity Thermogenesis) — 15-20%

Calories burned through daily movement that isn’t exercise.

Walking, fidgeting, standing, typing.

This varies HUGELY between people.

4. EAT (Exercise Activity Thermogenesis) — 5-10%

Calories burned through intentional exercise.

Surprisingly small percentage for most people.

How to Calculate TDEE

Step 1: Calculate BMR

Mifflin-St Jeor Equation (most accurate):

Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5

Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161

Step 2: Apply Activity Multiplier

Multiply BMR by activity factor:

Activity LevelMultiplierDescription
Sedentary1.2Desk job, no exercise
Light1.375Light exercise 1-3 days/week
Moderate1.55Moderate exercise 3-5 days/week
Active1.725Hard exercise 6-7 days/week
Very Active1.9Athlete, physical job + exercise

TDEE = BMR × Activity Multiplier

Example Calculation (Female)

30-year-old woman Height: 165 cm Weight: 65 kg Moderate exercise

BMR: (10 × 65) + (6.25 × 165) - (5 × 30) - 161 = 650 + 1031 - 150 - 161 = 1,370 calories

TDEE: 1,370 × 1.55 = 2,124 calories/day

Example Calculation (Male)

30-year-old male, 80kg, 180cm, moderately active:

BMR = 10(80) + 6.25(180) - 5(30) + 5 = 1,780 calories

TDEE = 1,780 × 1.55 = 2,759 calories/day

Using TDEE for Your Goals

Weight Loss

Eat below TDEE

Standard deficit: TDEE - 500 calories = ~1 lb lost per week Aggressive deficit: TDEE - 750-1000 calories = faster but harder

Example: TDEE of 2,124 → Eat 1,624 for weight loss

Muscle Gain

Eat above TDEE

Lean bulk: TDEE + 200-300 calories Standard bulk: TDEE + 500 calories

Example: TDEE of 2,124 → Eat 2,400-2,600 for muscle gain

Maintenance

Eat at TDEE

Weight stays stable. Good after reaching goal weight.

The Deficit Sweet Spot

Bigger deficit = faster weight loss, right?

Wrong.

  • 250 calorie deficit: Slow and sustainable. ~0.5lb/week
  • 500 calorie deficit: The sweet spot. ~1lb/week
  • 1,000+ deficit: Muscle loss, energy crashes, binge eating

A 500 calorie deficit is aggressive enough to see results, sustainable enough to maintain.

Why TDEE Calculators Are Just Estimates

Important caveat: All TDEE calculations are estimates.

They don’t account for:

  • Your specific metabolism
  • Genetic differences
  • Hormonal factors
  • NEAT variation (huge between individuals)
  • Daily variation

How to refine:

  1. Calculate estimated TDEE
  2. Eat that amount for 2 weeks
  3. Track weight
  4. Adjust based on results

Weight stable? TDEE is accurate. Gaining weight? TDEE is lower than calculated. Losing weight? TDEE is higher than calculated.

Common TDEE Mistakes

1. Overestimating activity level

Most people choose “moderate” or “active.”

Most people are actually “sedentary” or “light.”

Be honest. A desk job + 3 gym sessions = Light Activity.

2. Eating back exercise calories

Your Apple Watch says you burned 400 calories? It’s probably lying. Could be off by 30-50%. Don’t eat them back.

3. Ignoring weekends

Monday-Friday at a deficit means nothing if Saturday-Sunday you’re 1,000 over. The math still maths.

4. Not adjusting over time

TDEE changes as:

  • Weight changes
  • Age increases
  • Activity changes
  • Metabolism adapts

Recalculate every 10-15 lbs lost or every few months.

5. Expecting exact results

Your body isn’t a calculator. Water weight, hormones, and daily variation exist.

Look at trends over weeks, not daily fluctuations.

6. Using online calculators blindly

Every calculator gives different results.

Use them as starting points, then adjust.

The Simple System

  1. Calculate your TDEE
  2. Track your calories for one week (just observe)
  3. Eat 500 below TDEE
  4. Weigh yourself weekly (same time, same conditions)
  5. Adjust based on results

That’s literally it. No magic. Just math.

Quick TDEE Estimation

Don’t want to do math?

Rough estimate:

  • Sedentary: Weight (lbs) × 12-13
  • Light activity: Weight (lbs) × 13-14
  • Moderate activity: Weight (lbs) × 14-15
  • Active: Weight (lbs) × 15-16

150 lbs, moderate activity: 150 × 14.5 = 2,175 calories

Using CalorieCalculator

CalorieCalculator does the math for you:

  1. Enter your stats
  2. Select activity level
  3. Choose your goal
  4. Get your calorie target

Plus macro recommendations based on your goal.

FAQ

What’s the difference between BMR and TDEE? BMR is calories burned at rest. TDEE is BMR plus all activity.

Why is my TDEE so high/low? Height, weight, age, and activity level all factor in. Very tall/heavy people have higher TDEE.

Does muscle increase TDEE? Yes, but modestly. 1 lb of muscle burns ~6 extra calories per day. Don’t overestimate this.

How often should I recalculate TDEE? Every 10-15 lbs of weight change, or every 2-3 months.

Is 1200 calories ever appropriate? Rarely. For most adults, eating below BMR is dangerous and unsustainable. Consult a professional.

Why am I not losing weight at a deficit? Common reasons: tracking inaccuracy, TDEE overestimation, water retention, metabolic adaptation. Review your numbers.

Related reads:

— Dolce