TDEE Calculator

Estimate Total Daily Energy Expenditure (TDEE) — how many calories you burn each day — by calculating RMR (Mifflin–St Jeor or Katch–McArdle) and applying an activity multiplier. Use this to plan maintenance, weight loss, or gain targets.

Total Daily Energy Expenditure (TDEE): how to estimate calories for maintenance and goals

TDEE is an estimate of the total calories you burn in a typical day. It includes resting metabolic rate (RMR), the thermic effect of food (TEF), and energy spent in physical activity and exercise. Accurately estimating TDEE helps set sensible calorie targets for weight loss, maintenance or gain.

How this calculator works

The calculator first estimates RMR using either Mifflin–St Jeor (a widely validated equation based on weight, height, age, sex) or Katch–McArdle (which uses lean body mass derived from body fat %). It then multiplies RMR by an activity factor reflecting daily movement and exercise to produce a TDEE estimate. Finally, you can generate calorie targets for different weight goals.

Choosing an RMR method

Mifflin–St Jeor is a reliable default for most adults. Use Katch–McArdle when you have a reliable body fat percentage — it often better reflects the metabolic contribution of lean tissue. For clinical accuracy, indirect calorimetry remains the gold standard.

Activity multipliers

Standard multipliers approximate daily energy expenditure from activity. They are imperfect but useful:

  • 1.2 Sedentary — little or no exercise
  • 1.375 Light — light exercise 1–3 days/week
  • 1.55 Moderate — moderate exercise 3–5 days/week
  • 1.725 Very active — hard exercise 6–7 days/week
  • 1.9 Extra active — very hard exercise/physical job

Worked example

30-year-old male, 80 kg, 180 cm, BF 18%, moderate activity (×1.55):

  1. Mifflin RMR: 10×80 + 6.25×180 − 5×30 + 5 = 800 + 1125 −150 +5 = 1780 kcal/day.
  2. Katch (lean=80×(1−0.18)=65.6 kg): RMR = 370 + 21.6×65.6 ≈ 1779 kcal/day (very similar).
  3. TDEE = RMR × 1.55 ≈ 2760 kcal/day.

Setting calorie targets

For weight loss, a common safe deficit is 10–20% below TDEE for gradual loss; larger deficits increase risk of muscle loss and metabolic adaptation. For weight gain, a small surplus (5–15%) encourages lean gains without excessive fat.

Limitations and tips

  • Equations are population estimates and may be off for extremes of body composition or clinical conditions.
  • Use consistent measurements and re-evaluate after 2–4 weeks to adjust targets based on real weight change.
  • Consider professional assessment for sports or clinical needs.

This calculator is informational and not a substitute for medical advice.

Frequently Asked Questions

1. What's the difference between TDEE and RMR?
TDEE includes all daily energy expenditure (RMR + activity + TEF), while RMR is the resting portion alone.
2. Which activity level should I pick?
Choose the level that best matches your weekly movement; when in doubt, err on the conservative side and adjust after monitoring.
3. How fast should I lose weight?
Safe loss is typically 0.5–1% bodyweight per week; larger rates increase risk of muscle loss.
4. Can I trust Katch–McArdle?
It's useful if body fat % is accurate; otherwise Mifflin is safer as a default.
5. Do I include exercise calories?
Activity multipliers include typical exercise; for precise planning you can add planned exercise energy expenditure separately.
6. Will this adapt over time?
Metabolic rate can adapt with weight change — recalculate periodically and adjust targets accordingly.
7. Should I use macros or calories?
Calories set the energy goal; macronutrients (protein especially) help preserve lean mass during weight changes.
8. Is a 25% deficit OK?
25% is aggressive and may be appropriate short-term under supervision but often causes greater muscle loss and adherence issues.
9. How accurate are activity multipliers?
They're approximations; monitor weight trends and energy levels to fine-tune.
10. Can I use this for athletes?
Athletes should consider sport-specific energy needs and may require direct measurement and higher accuracy.