Calorie Calculator

BMR is the energy your body needs at complete rest just to keep vital functions running: breathing, circulation, cell repair, and organ activity. This calculator uses the Mifflin-St Jeor equation, published in 1990 and validated repeatedly as more accurate than the older Harris-Benedict formula for most adults:

Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5. Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161.

BMR alone underestimates real-world energy needs, because it ignores movement. Multiplying BMR by an activity factor produces TDEE, a realistic daily calorie target for someone who maintains that activity pattern consistently.

• Sedentary (little or no exercise): BMR × 1.2
• Lightly active (light exercise 1–3 days/week): BMR × 1.375
• Moderately active (moderate exercise 3–5 days/week): BMR × 1.55
• Very active (hard exercise 6–7 days/week): BMR × 1.725
• Extremely active (physical job plus daily training): BMR × 1.9

Most people overestimate how active they truly are; if you are unsure, pick a lower band and adjust after two to three weeks of tracking real body-weight trends.

Consider a 30-year-old woman who is 165 cm tall, weighs 65 kg, and exercises moderately. Her BMR = 10 × 65 + 6.25 × 165 − 5 × 30 − 161 = 650 + 1,031.25 − 150 − 161 ≈ 1,370 calories per day.

Applying the moderately active multiplier of 1.55 gives a TDEE of roughly 1,370 × 1.55 ≈ 2,124 calories per day. Eating close to that number should hold her weight steady over time, assuming her activity level stays consistent.

One kilogram of body fat stores roughly 7,700 calories of energy (about 3,500 calories per pound), so a sustained daily deficit of 500 calories below TDEE produces roughly 0.45 kg (1 lb) of fat loss per week — a pace considered safe and sustainable for most healthy adults. The same logic in reverse, a modest 250–500 calorie surplus alongside resistance training, supports gradual muscle gain without excessive fat gain.

Avoid extreme deficits below your BMR for extended periods; very low intake can slow metabolism, increase muscle loss, and trigger rebound overeating. Reassess your TDEE every few kilograms of weight change, since a smaller body burns fewer calories at rest.

If you only need the resting floor before applying an activity multiplier, the BMR Calculator isolates that step. Pairing TDEE planning with a BMI Calculator or Ideal Weight Calculator check can also help you set a realistic target weight range rather than chasing an arbitrary number.

Once you have a daily calorie number, how you split it between protein, carbohydrate, and fat shapes how sustainable and effective the plan feels day to day. Protein is generally the priority macronutrient during any calorie deficit, since it helps preserve lean muscle mass while you lose weight; many nutrition professionals suggest a starting range of roughly 1.6 to 2.2 grams of protein per kilogram of body weight for active adults, adjusted for individual goals and medical history.

Carbohydrate and fat can then be divided according to personal preference, training demands, and how each macronutrient makes you feel — some people perform and feel best on higher-carbohydrate, lower-fat diets, while others prefer the reverse, and both can work as long as total calories and protein intake stay on target.

This tool is for general screening and education only. It is not a medical device and does not replace advice from a doctor, dietitian, or other qualified health professional — especially if you are pregnant, under 18, managing a chronic condition, or taking medication that affects weight or metabolism.