Calorie & TDEE Calculator

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to sustain basic functions: breathing, circulation, and cell repair. This tool uses the Mifflin-St Jeor equation (1990), widely considered the most accurate for the general population: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age(years) + 5 for men; −161 for women. Compared to the older Harris-Benedict formula, Mifflin-St Jeor tends to be more accurate across body types.

TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. Sedentary (1.2×) means a desk job with almost no planned exercise. Lightly active (1.375×) is 1–3 days of moderate exercise per week. Moderately active (1.55×) is 3–5 days. Very active (1.725×) is intense training 6–7 days. Extra active (1.9×) is a physical job combined with daily hard training. If in doubt, most office workers should start with "Sedentary" and adjust after tracking for 2–3 weeks.

A deficit of 500 kcal/day below TDEE produces roughly 0.45 kg (1 lb) of fat loss per week, the evidence-based moderate rate. The aggressive loss column shows a 1,000 kcal deficit (about 0.9 kg/week). Neither figure drops below 1,200 kcal/day as a safety floor. Very low calorie diets without medical supervision cause muscle loss, hormonal disruption, and metabolic adaptation.

The maintenance macro split shown is 30% protein, 40% carbohydrates, 30% fat, a balanced starting point aligned with ICMR guidelines for moderately active adults. Protein is calculated at 4 kcal/g, carbs at 4 kcal/g, fat at 9 kcal/g. Athletes or those doing resistance training may want higher protein (35–40%) and lower carbs. These are starting points, not prescriptions.

Different tools use different formulas (Harris-Benedict, Katch-McArdle, Cunningham) and different activity multipliers. Mifflin-St Jeor with standard multipliers is the most widely validated for non-athletes. Differences of ±100–150 kcal between calculators are normal. Any calculated TDEE is an estimate; track your actual weight trend over 2–3 weeks and adjust intake by 100–200 kcal accordingly.

Recalculate whenever your weight changes by more than 3–4 kg, your activity level changes significantly, or you have been stuck at a plateau for 3+ weeks. Your TDEE shifts as your body composition changes: a lighter body burns fewer calories at rest, which is why calorie needs drop as you lose weight. A good habit is to recalculate every 4–6 weeks during an active cut or bulk.

For most healthy adults, a 500 kcal/day deficit is considered safe and sustainable. It targets roughly 0.45 kg of fat loss per week without triggering significant muscle loss or metabolic slowdown. A 1,000 kcal deficit accelerates fat loss but increases the risk of fatigue, nutrient deficiency, and muscle catabolism. If you feel persistently low-energy, reduce the deficit to 300–400 kcal and add a refeed day each week.

Research consistently shows that higher protein intake (30–35% of calories) preserves muscle mass during a calorie deficit better than lower-protein approaches. Beyond that, the carb-to-fat ratio is largely a personal preference and adherence issue. A 30% protein, 35% carbs, 35% fat split works well for most people. The most important variable is staying in a calorie deficit; macro ratios matter most at maintenance or in a small surplus.