Calorie Calculator

Your Basal Metabolic Rate (BMR) is the number of calories your body needs each day to keep your most basic functions running while completely at rest — breathing, circulation, cellular repair, brain activity, and core temperature regulation. BMR typically accounts for 60–75% of total daily energy expenditure. The Mifflin-St Jeor equation is the modern gold-standard formula and is the calculation method used by this tool.

Total Daily Energy Expenditure (TDEE) is BMR multiplied by an activity factor that reflects how much you move during the day. Sedentary office workers multiply BMR by 1.2; lightly active people by 1.375; moderately active by 1.55; very active by 1.725; and extremely active manual workers or athletes by 1.9. TDEE represents your maintenance calories — the intake at which your weight stays roughly stable.

To lose weight, eat 300–500 calories below your TDEE per day for sustainable fat loss of roughly 0.25–0.5 kg per week. Cutting more than 1,000 calories below TDEE is rarely advisable because it triggers metabolic adaptation, muscle loss, and rebound eating. To gain muscle in a calorie surplus, eat 200–400 calories above TDEE alongside a structured strength training program.

Macronutrient distribution matters as much as total calories for body composition. A common starting split is 30% protein, 40% carbohydrates, and 30% fats, but the optimal ratio depends on your goal. High-protein intakes (1.6–2.2 g per kg body weight) preserve muscle during cuts, support recovery during training, and increase satiety. Carbohydrates fuel performance; fats support hormones and absorption of fat-soluble vitamins.

Calorie calculators are estimates, not absolutes. Real-world energy expenditure varies with thyroid function, sleep quality, NEAT (non-exercise activity thermogenesis), genetics, and stress. Use the calculated TDEE as a starting target for two weeks, track actual weight changes, and adjust intake by 100–200 calories based on the trend. Your body's real-world TDEE is whatever number keeps your weight stable.

Enter your age, gender, height, and weight in metric (cm/kg) or imperial (ft-in/lb) units. Select an activity level that honestly reflects your daily life — most people overestimate this, which is why their cutting plans don't work. If you sit at a desk and exercise three to four times a week, you are 'lightly active', not 'very active'. Be honest with the input for an accurate output.

The result panel shows your BMR, maintenance TDEE, recommended weight-loss intake (typically 500 below TDEE), and recommended weight-gain intake (typically 300 above TDEE). The macro split shows grams per day for protein, carbs, and fat at the 30/40/30 distribution. Adjust these targets manually if you follow a specific diet style like keto, low-carb, or high-protein.

How accurate is this calculator? Mifflin-St Jeor is accurate to within ±10% for the general adult population. Highly muscular individuals may need to add 5–10% to BMR; people with significant excess body fat may need to subtract 5%. Treat the output as a starting point, validate it against two weeks of weight tracking, and adjust your daily intake by 100–200 calories based on what your body actually does.

Should I count calories every day forever? Most people benefit from 1–3 months of strict tracking to learn the calorie content of common foods, then transition to portion-aware intuitive eating with periodic check-ins. Long-term obsessive tracking can become disordered for some people — prioritize building sustainable habits over chasing perfect numbers indefinitely.

What is a safe rate of weight loss? 0.5–1% of body weight per week is the medically recommended range. Faster loss usually means muscle loss, hormonal disruption, and weight regain. Slower loss preserves muscle, sustains metabolism, and is far more likely to stick. The calorie deficit recommended by this tool is calibrated to that sustainable range.