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TDEE Calculator

Calculate your Total Daily Energy Expenditure with the Mifflin-St Jeor formula. Get instant calorie targets and macros for losing, maintaining, or gaining weight.

TDEE inputs

This calculator is for informational purposes only and is not a substitute for professional medical advice. Consult a qualified healthcare provider before making changes to your diet, exercise, or health regimen.

What is TDEE and why does it matter?

Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period. It is the single most useful number for anyone trying to lose, maintain, or gain weight, because it tells you exactly how much fuel your body needs each day. Eat less than your TDEE and you lose weight; eat more and you gain. There is no magic to it — energy balance is a law of physics.

Your TDEE is made up of four components. Basal Metabolic Rate (BMR) is the energy your body uses just to keep you alive — breathing, circulating blood, maintaining body temperature, repairing cells. It typically accounts for 60–70% of total burn. The thermic effect of food (TEF) is the energy spent digesting and processing what you eat, around 10% of total intake. Non-exercise activity thermogenesis (NEAT) covers everything you do that isn't sleeping, eating, or formal exercise — fidgeting, walking around the house, standing — and can vary enormously between individuals (100 to 800+ kcal/day). Finally, exercise activity thermogenesis (EAT) is the calories burned during structured workouts.

How this calculator works

We use the Mifflin-St Jeor equation, published in 1990 in The American Journal of Clinical Nutrition, which is currently considered the most accurate predictive equation for healthy adults. The Academy of Nutrition and Dietetics formally recommends it as the BMR estimate of choice for non-obese adults.

The equation is:

  • Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
  • Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161

We then multiply BMR by an activity factor drawn from FAO/WHO/UNU tables to estimate full TDEE:

  • Sedentary (1.2): desk job, little or no exercise.
  • Lightly active (1.375): light exercise 1–3 days a week.
  • Moderately active (1.55): moderate exercise 3–5 days a week.
  • Very active (1.725): hard exercise 6–7 days a week.
  • Extra active (1.9): physical job and hard daily training.

Most people overestimate their activity level. If you sit at a desk all day and train three times a week for an hour, you are moderately active, not very active. Be honest — the calculation is only as good as the input.

Worked example

A 35-year-old woman who weighs 68 kg, stands 165 cm tall, and trains three times a week (moderate):

  • BMR = (10 × 68) + (6.25 × 165) − (5 × 35) − 161 = 680 + 1031.25 − 175 − 161 = 1,375 kcal/day
  • TDEE = 1,375 × 1.55 = 2,131 kcal/day
  • To lose ~0.45 kg per week she would eat ~1,631 kcal/day (TDEE − 500).
  • To maintain: ~2,131 kcal/day.
  • To gain ~0.25 kg per week: ~2,431 kcal/day (TDEE + 300).

Choosing the right calorie target

A 500 kcal/day deficit is the textbook starting point for weight loss. It produces approximately 0.45 kg (1 lb) of fat loss per week — fast enough to stay motivated, slow enough to preserve muscle and avoid extreme hunger or fatigue. Larger deficits (750–1000 kcal/day) work for people with significant excess weight but are not appropriate for lean individuals or anyone with a history of disordered eating.

For weight gain, a smaller surplus is usually better. +200 to +400 kcal yields a steady 0.2–0.4 kg per week, which is roughly the maximum rate at which most adults can add lean mass without proportional fat gain. Larger surpluses just add fat.

Macros: protein, fat, and carbohydrates

Once you know your calorie target you can split it into macronutrients. Our defaults prioritise protein because the research is unambiguous: higher protein protects lean mass during weight loss, supports muscle growth during training, and is more satiating than fat or carbs.

  • Cutting: 2.2 g protein per kg, 0.8 g fat per kg, carbohydrates fill the rest.
  • Maintaining or bulking: 1.8 g protein per kg, 1.0 g fat per kg, carbohydrates fill the rest.

These are general defaults. Endurance athletes typically need more carbohydrates, strength athletes can push protein higher, and people on ketogenic diets shift fat and carbs in opposite directions. Adjust to your training, preferences, and how you actually feel and perform.

How accurate is TDEE estimation?

Predictive equations like Mifflin-St Jeor are accurate to within roughly ±10% of measured BMR for most healthy adults of normal weight. They become less accurate for very lean athletes (where lean mass per kg of body weight is much higher than average), individuals with very high body fat, the elderly, and people with thyroid or other metabolic conditions.

The right way to use any TDEE calculator is as a starting estimate. Eat the suggested target consistently for 10–14 days, weigh yourself daily, average the weights weekly, and look at the trend. If you are losing or gaining faster or slower than expected, adjust by 100–200 kcal and re-measure. After two iterations your real-world TDEE is much more accurate than any equation.

Common mistakes

  • Overestimating activity. Most people pick "very active" when they should pick "moderate". Be honest about your average week, not your best week.
  • Ignoring weight change. Your TDEE drops as you lose weight and rises as you gain. Recalculate every 2–4 kg of change.
  • Eating back exercise calories twice. If you used an activity multiplier of 1.55 you have already accounted for exercise. Don't add another 500 kcal because your watch told you to.
  • Treating the number as a hard limit. ±100 kcal per day is well within natural variation in measurement, hydration, and digestion. Average over a week.
  • Setting unrealistic deficits. A 1,000+ kcal/day deficit is rarely sustainable and tends to backfire through binge cycles, muscle loss, and metabolic adaptation.

When to consult a professional

A TDEE calculator is a good general tool, but it cannot replace personalised advice from a qualified professional. Talk to a doctor or registered dietitian if you have a chronic condition (diabetes, thyroid disease, eating disorders), are pregnant or breastfeeding, are under 18 or over 65, are training for a competitive event, or simply want a more accurate metabolic measurement (clinics can perform indirect calorimetry, which measures BMR directly via gas exchange).

Frequently Asked Questions

What is TDEE?
TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in 24 hours, including basal metabolism, the thermic effect of food, non-exercise activity, and exercise. It is the most useful single number for planning weight loss, maintenance, or gain.
How is TDEE calculated?
TDEE = BMR × activity multiplier. BMR (Basal Metabolic Rate) is computed with the Mifflin-St Jeor equation. The activity multiplier (1.2 to 1.9) accounts for daily movement and exercise. This calculator uses the formulas published in Mifflin et al., 1990 and the FAO/WHO/UNU activity tables.
Mifflin-St Jeor or Harris-Benedict — which is more accurate?
For most healthy adults, Mifflin-St Jeor (1990) is more accurate than the original Harris-Benedict equation (1919) and the revised Roza version (1984). Studies show Mifflin-St Jeor is within ±10% of measured BMR for ~80% of non-obese adults. We default to Mifflin-St Jeor and offer Harris-Benedict for comparison.
Why do I need to know my activity level?
BMR alone only covers about 60–70% of your total burn. Movement — whether structured exercise or just walking around — adds 20–40%. The activity multiplier turns your BMR into your full daily energy expenditure. Pick the level that honestly reflects your week, not the level you wish you trained at.
How accurate is this calculator?
Population-average accuracy is ±10% for healthy adults of normal weight. Accuracy drops for very lean athletes (where lean mass dominates BMR), people with very high body fat, and individuals with thyroid or other metabolic conditions. Use the result as a starting point, then adjust based on actual weight change over 2–3 weeks.
Should I eat my BMR or my TDEE?
Neither — eat the calorie target that matches your goal. To lose weight, eat below TDEE (we suggest TDEE − 500 for ~0.45 kg / 1 lb per week). To maintain, eat at TDEE. To gain, eat above TDEE (we suggest +300). Eating below BMR for sustained periods is generally not recommended.
How much protein, fat, and carbs should I eat?
Our default macro split prioritises protein (2.2 g per kg of bodyweight when cutting, 1.8 g/kg otherwise), holds fat at 0.8–1.0 g/kg, and fills the remainder with carbohydrates. These ratios protect lean mass during weight loss and support training. Vegetarians, athletes, and people with specific medical conditions may need different splits.
Why does my TDEE seem too low / too high?
Common causes: (1) overestimating activity level — most people overestimate; (2) measurement errors in weight or height; (3) very high or very low body fat percentage, which Mifflin-St Jeor does not account for; (4) genetic and hormonal variation of ±10%. Track your actual intake and weight for 2 weeks, then adjust.
Does TDEE change as I lose or gain weight?
Yes. Both BMR and the calorie cost of activity scale with body mass. As you lose weight your TDEE drops; as you gain it rises. Recalculate every 2–4 kg (5–10 lb) of change. There is also a metabolic adaptation effect during prolonged dieting where TDEE drops slightly more than the math predicts.
Is this a substitute for medical advice?
No. This calculator is for general informational purposes only. If you have a medical condition, are pregnant or breastfeeding, are under 18, or are planning a significant change to your diet or training, consult a qualified healthcare professional or registered dietitian.