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Calorie Deficit & TDEE Calculator
Total Daily Energy Expenditure and calories for weight loss or gain.
How it works
This calculator first estimates your basal metabolic rate with the Mifflin-St Jeor equation, which uses weight, height, age and sex. It then multiplies that resting figure by an activity factor, from 1.2 for a sedentary routine up to 1.9 for very heavy daily activity, to give total daily energy expenditure: the calories you burn in a typical day. The deficit and surplus figures are simple adjustments to that total, not prescriptions, and they assume your activity level stays as selected.
How to read the result
If you eat at your TDEE, your weight should stay roughly stable. Eating below it, consistently, leads to loss; eating above it leads to gain, though the speed varies with sleep, stress, food choices and how accurately intake is tracked. A moderate deficit is easier to sustain than an aggressive one, and a small surplus with strength training favours muscle over fat gain. Expect week-to-week noise from water retention and weigh trends over several weeks.
One practical tip
Pick the activity level that describes your ordinary weeks, not your best week. Overstating activity is the most common reason a calculated target feels too high. If your weight does not move after three honest weeks, adjust by 200 calories and reassess, rather than overhauling everything at once.
Revisit the calculation whenever your weight changes by several kilograms or your activity pattern changes for a sustained period, because both shift the underlying estimate and a stale target can quietly stop matching your real expenditure.