Your daily calorie needs, honestly estimated
Your daily calorie needs, honestly estimated
Total daily energy expenditure — TDEE — is everything you burn in a day. It combines your resting metabolic rate with the energy used by movement, exercise, and digesting food. Enter your details and activity level to see your maintenance figure and targets for losing or gaining weight.
The calculation runs in two steps. First, the Mifflin-St Jeor equation estimates BMR:
Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161
Then BMR is multiplied by an activity factor between 1.2 and 1.9 to produce TDEE.
This is where most estimates go wrong, and it is worth being deliberately conservative. The multipliers describe your whole life, not your best week.
If you are between two levels, take the lower one. It is far easier to add calories when the scale is not moving than to work out why an aggressive estimate is not producing results.
A pound of body fat represents roughly 3,500 calories, so a deficit of 500 a day corresponds to approximately a pound a week. That figure is a useful approximation rather than a physical law — real weight change is messier because water, glycogen, and adaptation all interfere.
For fat loss, a deficit of 15–25% below TDEE is a reasonable range. Larger deficits produce faster scale movement but cost more lean tissue and are considerably harder to sustain. Roughly 0.5–1% of body weight per week is a sensible pace.
For muscle gain, a surplus of 10–15% is usually enough. Muscle is built slowly — realistically a few pounds per year for someone past the beginner stage — and a larger surplus mostly adds fat rather than accelerating the process.
Prediction equations are population averages. Individual metabolic rates vary by around 10% in either direction at the same height, weight, age, and sex, driven mainly by differences in lean mass and non-exercise movement.
Fitness trackers and gym machines typically overestimate calories burned, sometimes substantially. Food labels carry a permitted margin of error, and portion estimation adds more. In practice these errors stack in the same direction: intake is underestimated and expenditure overestimated.
The reliable method is to use the calculator as a starting point, hold that intake steady for two to three weeks while tracking weight, and adjust from what actually happens. Your own trend data beats any equation.
Energy balance determines weight, but it says nothing about health, body composition, or how you feel. The same 2,000 calories can leave you satisfied and energetic or hungry and depleted depending on composition.
Adequate protein preserves muscle in a deficit and is the most satiating macronutrient. Fibre from vegetables, fruit, and whole grains supports fullness at low calorie cost. Sufficient fat matters for hormone production. And sleep affects appetite regulation strongly enough that chronic short sleep undermines otherwise sound plans.
This tool gives general estimates for healthy adults. If you are pregnant or breastfeeding, managing a condition such as diabetes or thyroid disease, taking medication that affects weight or appetite, recovering from an eating disorder, or under 18, the right calorie target is a clinical question rather than a formula. A doctor or registered dietitian can account for factors no calculator can see.
A deficit of 15-25% below your maintenance figure is a common range, corresponding to roughly 0.5-1% of body weight lost per week. Larger deficits work faster but cost more lean tissue and are harder to sustain.
The most frequent causes are underestimating portions, overestimating exercise burn, and an activity multiplier set too high. Water retention can also mask fat loss for weeks. Track consistently for two to three weeks before concluding the number is wrong.
For most adults that is very low and difficult to meet nutrient needs on. It is sometimes used under supervision for specific reasons, but it is not a sensible default. Speak to a doctor or dietitian before eating at that level.
If you selected an activity level that already reflects your training, exercise is included in the figure and eating it back again would double-count. Only add calories separately if you chose a sedentary multiplier and train on top of it.