TDEE calculator: daily calories from the Mifflin-St Jeor equation
Your total daily energy expenditure (TDEE) is your resting metabolic rate times an activity factor. This calculator estimates the resting rate with the Mifflin-St Jeor equation, multiplies it by your activity level, and shows a moderate deficit and surplus. Treat the result as a starting point and adjust after two to three weeks of real weigh-ins.
- Maintenance (TDEE)
- 2,184 kcal
- per day, to keep weight steady
- Resting rate
- 1,409 kcal
- Fat loss start
- 1,684 kcal
- about −500 a day
- Lean gain start
- 2,434 kcal
- about +250 a day
How it works
Resting rate (Mifflin-St Jeor)
Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. Women: the same with −161 instead of +5. It is the equation most dietitians use when body fat is unknown.
Activity factor
Sedentary 1.2, light 1.375, moderate 1.55, very active 1.725, athlete 1.9. Most people overestimate their activity; when in doubt, pick one level lower.
Targets
A deficit of about 500 kcal a day is a common starting point for fat loss, and a surplus of about 250 to 300 kcal for lean gain. Your weight trend over weeks is the real test.
Questions
How accurate is a TDEE calculator?
Equations are typically within about 10% of measured resting energy for most adults, and less accurate at the extremes of body size. Use the number to start, then adjust by your 7-day average weight over two to three weeks.
Should I eat back the calories I burn exercising?
The activity factor already includes your usual training. Adding watch estimates on top usually double-counts, so keep the TDEE target and adjust from your weight trend.
What deficit is safe?
Around 500 kcal a day, or losing about 0.5% to 1% of body weight a week, is a common target. Very low intakes are not advised without medical supervision.
Why does my weight not match the math?
Water, salt, carbohydrate and digestion move daily weight by a kilogram or more. Compare 7-day averages, not single days.
Related calculators
Sources
Accurate as of November 12, 2026. Training and nutrition guidance only, not medical advice. See a clinician for symptoms, injury or a medical condition.
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