The good news is that our macro calculator adapts based on your goals: Health Improvement: The calculator uses weight maintenance calories from the validated NIH algorithm, ideal for those focusing on overall health. Fat Loss or Muscle Gain: The calculator utilizes the NIH algorithm considering anthropometric data, desired goal time frame. It also takes into account the dynamic nature of metabolism – perfect for those aiming to shed fat or bulk up. Athletic Performance Enhancement: It adds an extra 10% to the weight maintenance requirements from the NIH algorithm. This is ideal for individuals who want to boost their athletic performance with increased calorie needs. Body Composition Transformation: It cuts calorie requirements by approximately 10% from NIH algorithm’s weight maintenance requirements. Perfect for those aiming to simultaneously lose fat and gain muscle.