How this calculator works
Your body uses energy at rest and during movement, digestion and daily life. The Mifflin–St Jeor equation estimates resting energy expenditure from age, height, weight and sex; an activity multiplier converts that into total daily energy expenditure (TDEE).
For fat loss the calculator subtracts a moderate 400 kcal; for muscle gain it adds 250 kcal. Those adjustments are deliberately conservative. Large changes can make adherence, training and recovery harder without making the underlying estimate more accurate.
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age, with a sex-specific constant. BMR is then multiplied by an activity factor to estimate TDEE.
How to use the result
Treat the output as a starting hypothesis, not a calorie prescription. Log consistently for two to four weeks, compare weekly-average body weight, and adjust by roughly 100–200 kcal only when the trend clearly differs from the goal.
Activity categories are the largest source of error. A desk job plus four gym sessions may still fit “moderate,” while a physical job can raise expenditure even without formal exercise. Your own trend is more informative than the label.
Get a more reliable result
Use a recent morning weight, measured height and your current age. Choose the activity level that describes an average week, including work and routine movement—not the busiest day you can remember. If your step count or training volume changes sharply between weeks, calculate from the pattern you can actually repeat.
Common errors that change the answer
- Selecting “very active” because one workout feels hard, while the rest of the day is sedentary.
- Comparing the estimate with one day of scale weight instead of a multi-week average.
- Treating calories burned by a watch as extra food after activity is already included in the multiplier.
What to do next
- Keep intake reasonably consistent for 14 days before judging the estimate.
- Compare seven-day weight averages, not Monday with Tuesday.
- Recalculate after a meaningful weight or activity change.
Guides that support this calculator
Frequently asked questions
Is TDEE the same every day?
No. Steps, training, sleep, food intake and spontaneous movement vary. TDEE is a useful average, not a fixed daily bill.
Why is my tracker different?
Wearables, food apps and equations use different models. None directly measures free-living expenditure; use your weight trend to calibrate.
Should I eat below BMR?
BMR is not a minimum-intake rule, but a target far below estimated needs can be difficult to sustain and may be inappropriate. Get individual advice for aggressive plans.