TDEE & Calorie Deficit Calculator

Find out exactly how many calories you need each day — and how many to cut to lose fat, maintain weight, or build muscle. No guessing. Just your numbers.

Enter your details

Your TDEE
kcal/day (maintenance)
Target calories
kcal/day for your goal
Est. weekly change
kg per week
Calorie deficit/surplus
kcal vs maintenance

Daily macros

Protein
Carbs
Fats

What Is TDEE and Why Does It Matter?

Your Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day — factoring in your basal metabolic rate (the calories burned just to keep you alive) plus all physical activity. It’s your true maintenance number: eat at this level and your weight stays the same.
 
Understanding your TDEE is the foundation of any successful diet. Without it, you’re guessing. Too big a deficit and you lose muscle along with fat. Too small and progress stalls. The right deficit — typically 300-500 calories below your TDEE — gives you consistent fat loss without sacrificing muscle or energy.
 
The calculator above uses the Mifflin-St Jeor equation, which research consistently shows is the most accurate formula for estimating BMR across different body types and ages.

How to Use Your Results

Your TDEE result is a starting point, not a fixed number. Here’s how to apply it:
 
1. Track for 2 weeks. Log your food and weigh yourself daily (average the readings). If your weight isn’t moving in the direction you expect, adjust calories by 100-150 kcal up or down.
 
2. Hit your protein target first. Protein is the most important macro for body composition — it preserves muscle during a cut and supports growth during a bulk. Hit this number every day before worrying about carbs or fats.
 
3. Fill remaining calories with carbs and fats. The split between carbs and fats is flexible and personal. Some people feel better with more carbs, others with more fat. The calculator gives you a solid starting point but you can adjust.
 
4. Reassess every 4-6 weeks. As you lose or gain weight, your TDEE changes. Recalculate every month or whenever your weight changes by more than 3-4kg.

What Affects Your TDEE?

Several factors determine how many calories you burn each day:

Age: Metabolism naturally slows with age, typically by about 1-2% per decade after 30. This is partly due to hormonal changes and partly due to gradual muscle loss — which is why strength training becomes more important as you age.

Muscle mass: Muscle tissue burns roughly 3x more calories at rest than fat tissue. This is why two people with the same weight and height can have very different TDEEs — the person with more muscle burns significantly more calories doing nothing.

Activity level: This is the biggest variable and the one most people underestimate. A sedentary desk worker burns around 300-500 fewer calories per day than someone with an active job or who trains 5+ days per week.

Body weight: Heavier bodies require more energy to move and maintain. As you lose weight, your TDEE decreases, this is why calorie needs to be recalculated as you progress.

Frequently Asked Questions

Yes — if you consistently eat fewer calories than your TDEE, you will lose weight. The size of the deficit determines the speed of loss. A 500 kcal daily deficit equals roughly 0.45kg per week. However, the quality of what you lose (fat vs muscle) depends heavily on how much protein you eat and whether you strength train.
A deficit of 300-500 calories per day is considered the sweet spot for most people. It’s aggressive enough to produce noticeable fat loss (0.3-0.5kg per week) while being sustainable long-term and small enough to preserve muscle mass. Deficits larger than 750-1000 kcal increase the risk of muscle loss, fatigue, and metabolic adaptation.
This calculator uses the Mifflin-St Jeor equation, which studies show is accurate to within 10% for most people. The biggest source of error is the activity multiplier — most people slightly overestimate their activity level. If in doubt, choose one level lower than you think, then adjust based on real-world results after 2 weeks of tracking.
For fat loss, prioritize protein at 1.8-2.2g per kg of bodyweight to protect muscle. Then allocate 25% of your total calories to fat (essential for hormones), and fill the remaining calories with carbohydrates. The calculator above does this automatically based on your goal — select “Cut” to get fat-loss specific macro targets.
Women generally have a lower TDEE than men of the same height and weight, primarily because men typically carry more muscle mass and have higher testosterone levels. On average, women’s TDEE is 200-400 kcal lower than men’s. The Mifflin-St Jeor formula this calculator uses accounts for this difference automatically through separate male and female equations.
Recalculate every 4-6 weeks, or any time your weight changes by more than 3-4kg. As you lose fat, your TDEE decreases because your body has less mass to maintain. This is why weight loss often stalls — your original deficit is no longer a deficit. Regular recalculation keeps you on track.
For most adults, 1200 calories is too low and creates an unnecessarily large deficit. Very low calorie diets increase muscle loss, cause fatigue, disrupt hormones, and are extremely difficult to sustain. The only situation where very low calories might be appropriate is under medical supervision. For sustainable fat loss, a 300-500 kcal deficit below your calculated TDEE is far more effective long-term.
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to keep your heart beating, lungs breathing, and organs functioning. TDEE is your BMR multiplied by an activity factor that accounts for movement, exercise, and daily activity. TDEE is always higher than BMR and is the number you should use for calorie planning.

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