BMI (Body Mass Index) is a measurement of body fat based on height and weight that applies to both men and women between the ages of 18 and 65 years.
BMI can be used to indicate if you are overweight, obese, underweight or normal. A healthy BMI score is between 18.5 and 24.9. A score below 18.5 indicates that you may be underweight; a value above 24.9 indicates that you may be overweight.
BMR (Basal Metabolic Rate) is the amount of energy expended on a daily basis by humans while at rest.
This site uses the Mifflin-St. Jeor equation to estimate your BMR. The Mifflin-St. Jeor formula is seen as a more accurate way to estimate your BMR than the more commonly know Harris Benedict Equation.
Mifflin-St. Jeor Equation
TDEE (Total Daily Energy Expenditure) is a method used alongside the BMR to calculate the amount of calories your body needs to function in a day based on your activity levels. These levels are grouped as follows: