# Health Calculator > Calculate your Body Mass Index (BMI) and Basal Metabolic Rate (BMR) with Metric and Imperial support. **Category:** Health **Keywords:** bmi, bmr, health, fitness, body mass index, calories, weight, height, calculator, metabolism, diet **URL:** https://complete.tools/health-calc ## How it calculates The calculations performed by Health Calc rely on established formulas. For BMI, the formula is: BMI = weight (kg) ÷ (height (m) × height (m)). Here, 'weight' is the person's weight in kilograms and 'height' is their height in meters. For calculating daily caloric needs, the Mifflin-St Jeor Equation is used. For men, the formula is: BMR = 10 × weight (kg) + 6.25 × height (cm) - 5 × age (years) + 5. For women, the formula is: BMR = 10 × weight (kg) + 6.25 × height (cm) - 5 × age (years) - 161. The BMR is then multiplied by an activity factor (ranging from 1.2 for sedentary to 1.9 for very active) to estimate total caloric needs. Each of these calculations has a direct relationship to the variables involved, providing insights into health and nutrition. ## Who should use this 1. Dietitians assessing clients' body weight and caloric needs for meal planning. 2. Fitness trainers calculating BMI and caloric intake for personalized fitness programs. 3. Healthcare professionals monitoring patients' weight management progress. 4. Nutrition researchers analyzing population health data related to BMI and dietary habits. ## Worked examples Example 1: A 70 kg male, 1.75 m tall, 30 years old, sedentary lifestyle. To calculate BMI: BMI = 70 ÷ (1.75 × 1.75) = 22.86. For daily caloric needs: First, calculate BMR using the male formula: BMR = 10 × 70 + 6.25 × 175 - 5 × 30 + 5 = 1,647.5. Multiply by the activity factor of 1.2 for sedentary: Daily Caloric Needs = 1,647.5 × 1.2 = 1,977.0. Example 2: A 60 kg female, 1.60 m tall, 25 years old, moderately active. For BMI: BMI = 60 ÷ (1.6 × 1.6) = 23.44. For daily caloric needs: BMR = 10 × 60 + 6.25 × 160 - 5 × 25 - 161 = 1,348. BMR is multiplied by 1.55 for moderate activity: Daily Caloric Needs = 1,348 × 1.55 = 2,092.4. ## Limitations Health Calc has several limitations. First, the BMI calculation does not distinguish between muscle and fat mass, potentially misrepresenting body composition in athletes. Second, the Mifflin-St Jeor Equation is based on averages and may not accurately reflect caloric needs for individuals with unique metabolic conditions. Third, the tool assumes a linear relationship between weight, height, age, and physical activity, which may not hold true for all populations. Lastly, results may be inaccurate for those at extreme ends of height and weight spectra, as the formulas are less validated for these groups. ## FAQs **Q:** How does the tool account for differences in body composition when calculating BMI? **A:** The tool does not account for body composition differences, as BMI is a simple ratio of weight to height and does not differentiate between fat and muscle mass. **Q:** What are the potential inaccuracies in caloric needs calculations? **A:** Caloric needs calculations may be inaccurate for individuals with atypical body compositions, metabolic disorders, or those who engage in extreme exercise regimens that the activity multipliers do not adequately represent. **Q:** Can the tool provide recommendations based on the calculated values? **A:** Health Calc does not provide personalized recommendations; it only calculates values based on user inputs without considering individual health conditions or goals. **Q:** Are the formulas used clinically validated? **A:** Yes, the formulas for BMI and BMR used in Health Calc are clinically validated and commonly accepted in health and nutrition fields. --- *Generated from [complete.tools/health-calc](https://complete.tools/health-calc)*