Nutrition & Diet Calculators

The right nutrition calculator depends on your dietary goal. If you are trying to understand how many calories you need each day, start with the calorie calculator. It uses the Mifflin-St Jeor equation, one of the most accurate methods for estimating resting metabolic rate, combined with your activity level to determine your total daily energy expenditure.

For weight management, understanding your caloric balance is fundamental. A deficit of approximately 500 calories per day generally results in about one pound of weight loss per week, while a surplus supports muscle gain when combined with resistance training. Our calculator helps you find the right target for your specific goals.

Remember that calorie calculators provide estimates based on averages. Individual metabolism can vary by 5% to 15% from calculated values due to genetics, body composition, and other factors. Use the calculated targets as a starting point and adjust based on your actual results over two to four weeks.

Nutrition science revolves around understanding how the food you eat fuels your body. Calories are the unit of energy that food provides, and your body requires a certain number of calories each day to perform basic functions like breathing, circulation, and cell repair (your basal metabolic rate) plus the energy needed for physical activity and digestion.

The three primary macronutrients each serve distinct roles. Protein (4 calories per gram) supports muscle repair, immune function, and enzyme production. Most adults need 0.8 to 1.0 grams per kilogram of body weight daily, with higher amounts (1.2 to 2.0 g/kg) beneficial for active individuals. Carbohydrates (4 calories per gram) are the body's preferred energy source, particularly for brain function and high-intensity exercise. Fats (9 calories per gram) are essential for hormone production, nutrient absorption, and cell membrane integrity.

The Mifflin-St Jeor equation, developed in 1990 and validated in numerous studies, is considered one of the most accurate predictive equations for estimating resting metabolic rate in healthy adults. It calculates BMR based on weight, height, age, and biological sex, then multiplies by an activity factor to estimate total daily energy expenditure (TDEE).

Beyond calories, micronutrients including vitamins and minerals play critical roles in health. A balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats typically provides adequate micronutrients for most people. When calorie intake is restricted for weight loss, paying extra attention to nutrient density becomes important to avoid deficiencies.