Calorie Calculator

Your daily calorie needs depend on your age, sex, height, weight, and activity level. The calculator estimates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation. Most adults need between 1,600 and 3,000 kcal per day depending on these factors.

The Mifflin-St Jeor equation is the most widely recommended formula for estimating Basal Metabolic Rate (BMR). For men it is: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5. For women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161. Your BMR is then multiplied by an activity factor to get your TDEE.

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to maintain basic functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor to account for the calories you burn through daily movement and exercise.

A safe and sustainable rate of weight loss is 0.5 to 1 pound per week, which requires a daily calorie deficit of approximately 250–500 kcal below your maintenance calories. Losing more than 2 pounds per week is generally considered extreme and may be difficult to sustain without affecting muscle mass or nutritional intake.

To gain weight and build muscle, you need to eat more calories than you burn — typically 250–500 kcal above your maintenance level per day. A moderate surplus of about 250 kcal/day (roughly +0.5 lb/week) is generally recommended to minimize excess fat gain while supporting muscle growth.

Yes, significantly. An activity multiplier ranging from 1.2 (sedentary) to 1.9 (very active) is applied to your BMR. For a person with a BMR of 1,700 kcal, this means daily needs could range from about 2,040 kcal (sedentary) to 3,230 kcal (very active) — a difference of nearly 1,200 kcal per day.

In terms of energy, one calorie (kcal) always provides the same amount of energy regardless of food source. However, the macronutrient source matters for satiety, metabolism, and health. Protein (4 kcal/g) supports muscle; carbohydrates (4 kcal/g) provide quick energy; and fats (9 kcal/g) are the most calorie-dense macronutrient.

This calculator provides a scientifically based estimate using the Mifflin-St Jeor equation, which is considered accurate within 10% for most people. Individual factors like genetics, hormonal status, sleep quality, and medication can affect actual calorie needs, so treat the result as a starting point and adjust based on real-world progress.