BMI Calculator

Use the calculator below to accurately compute your BMI and the health category:


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The BMI calculator uses the following weight categories for your BMI score:

Underweight = less than 18.5
Normal weight = 18.5 – 24.9
Overweight = 25.0 – 29.9
Obese = 30.0 or greater


What is BMI

Body Mass Index (BMI) represents an index of body weight in relation to height. While BMI is not a measure of body fat, it is recommended as a more accurate way to assess body fatness than measuring weight alone.

In general, people with BMI in Normal range have the lowest health risks.

However, higher BMI does not always mean that a person has too much fat. Although BMI correlates with body fat level, it is not the perfect tool for evaluating the health risks associated with obesity. For example, athletes may have BMI which is higher than Normal because they have more muscle and thus weigh more than average people. But despite their high BMI, they are fit and in good health.

At the same time, BMI which is lower than Normal is usually associated with either extreme natural leanness or, in a worse case, with malnutrition or even starvation.


BMR Calculator

Use the calculator below to compute your daily BMR rate – the minimum daily calories required to maintain the essential body functions (not including extra calories required for activities such as exercise):


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What is BMR

The rate at which energy (calories) is used for the essential life functions is called Basal Metabolic Rate (BMR). Basal metabolism includes most of the involuntary things the human body does to support life – such as breathing, blood circulation, body temperature regulation, nervous system operations, etc., but not the extra energy needed for any additional physical activity such as gym exercise.

In other words, if you laid in bed all day doing nothing else, then you would need to eat at least the number of calories roughly equal to your BMR in order to maintain your normal body functions.

Basal metabolism consumes from 60 to 70% of body’s total daily calories expenditure.

What is RMR

Resting Metabolic Rate (RMR) is equivalent to BMR but is measured under less strict conditions. BMR usually assumes special lab conditions where even the room temperature has to be exact. RMR is the BMR value adjusted for the regular life environment.

RMR values are about 15% higher than the BMR values.

In your diet calculations, you can safely use RMR instead of the scientifically precise BMR.



A 6′ Tall 30 year old man that weighs 190 lbs has a BMR of 1960. So he burns 1960 calories per day at rest.

Now, the BMR does not include extra calories burned throughout the day through exercise and other daily activities. So next we need to add an Activity Multiplier to the BMR number. This is very easy to do using the popular and fairly accurate Harris-Benedict equation.

Take your BMR and multiply it by your daily activity level closest match from the list below


Harris Benedict Activity Formula

  • Sedentary (little or no exercise) – BMR x 1.2
  • Lightly Active (light exercise or sport 1 – 3 days per week) – BMR x 1.375
  • Moderately Active (moderate exercise or sport 3 – 5 days per week) – BMR 1.55
  • Very Active (hard exercise or sport 6 – 7 days per week) – BMR x 1.725
  • Extremely Active (very intense exercise or sports plus physically demanding job) – BMR x 1.9


Let’s say the example male used with a BMR of 1960 exercises 3 days per week and is fairly active throughout the day. He would choose the moderately Active activity level and would multiply it by his BMR.

BMR 1960 x 1.55 (Moderately active) = 3038

We now know that on average he burns 3038 calories per day through natural body functions and activity. This is his calorie maintenance level. So to maintain his current body weight he will consume 3038 calories per day.