Body Mass Index (BMI) and Basal Metabolic Rate (BMR) Calculators


BMI & BMR Calculator

BMI and BMR Calculator

Height: cm

Weight: kg



Physical activity level:

Your BMI is:

Your BMI range:

Your BMR is: calories/day

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Body Mass Index (BMI) and Basal Metabolic Rate (BMR) are two important measurements that can be used to assess overall health.

BMI is a measure based on height and weight. It is calculated by dividing a person’s weight in kilograms by their height in meters squared. A BMI of 18.5 to 24.9 is considered healthy, while a BMI of 25 or higher is considered overweight. BMI is a useful tool for determining if a person is at risk for weight-related health problems, such as diabetes and heart disease.

BMR is the number of calories a person burns per day. It is the amount of energy needed to keep the body functioning. BMR can be affected by factors such as age, gender, muscle mass, and weight. A higher BMR means that a person burns more calories.

BMI explained

Body Mass Index (BMI) is broken down into different ranges, they are:

Underweight: A BMI of less than 18.5 is considered underweight. People in this category may be at risk for nutrient deficiencies and other health problems.

Normal weight: A BMI of 18.5 to 24.9 is considered healthy. People in this category are at a lower risk for weight-related health problems.

Overweight: A BMI of 25 to 29.9 is considered overweight. People in this category are at an increased risk for weight-related health problems such as diabetes, heart disease, and high blood pressure.

Obese: A BMI of 30 or higher is considered obese. People in this category are at a very high risk for weight-related health problems and have a higher risk of developing serious health problems such as diabetes, heart disease, and certain cancers.

It’s important to note that BMI is not a perfect measure of health, as it doesn’t take into account muscle mass, body composition, and distribution of body fat. Additionally, certain populations such as athletes and pregnant women may have a different interpretation of the ranges. Therefore, it’s always recommended to consult with a healthcare professional for a better and more complete assessment of one’s health.

BMR explained

Our calculator uses the Mifflin-St Jeor equation which is a widely used equation for estimating a person’s Basal Metabolic Rate (BMR). This is the estimated amount of energy the body burns at rest to maintain normal bodily functions such as breathing, digestion, and heart rate. BMR is often used as a starting point for determining a person’s total daily energy expenditure, which takes into account a person’s physical activity level in addition to their BMR.

The Mifflin-St Jeor equation is considered to be one of the most accurate equations for estimating BMR, and it takes into account a person’s weight, height, age, and gender. The equation is as follows:

For Men: BMR = (10 * weight in kg) + (6.25 * height in cm) – (5 * age in years) + 5

For Women: BMR = (10 * weight in kg) + (6.25 * height in cm) – (5 * age in years) – 161

The equation is then multiplied by a physical activity factor to estimate total daily energy expenditure. For example, a sedentary person, the physical activity factor would be 1.2, for a lightly active person it would be 1.375 and so on.

It’s important to note that the Mifflin-St Jeor equation is just an estimate, and it may not be accurate for everyone. Factors such as muscle mass, body composition, and genetics can also play a role in a person’s BMR. Additionally, BMR changes with age, illness, hormonal changes and other conditions, so it’s important to regularly recalculate your BMR if you notice any changes in your body. 

Knowing your personal BMR is a helpful tool when trying to lose weight. By restricting your diet by the recommended 500 calories per day you will lose approximately 1 pound per week. Studies have shown that this will result in sustainable weight loss, and the best type of weight loss is when it stays off!


Understanding both BMI and BMR can be beneficial for those looking to improve their health. By maintaining a healthy BMI, a person can reduce their risk of weight-related health problems. Increasing BMR by exercising regularly will help a person burn more calories each day, which can help with weight loss and overall health.

It is important to note that these measurements are not the only indicators of health, and should be used in combination with other health markers like blood pressure, cholesterol, and glucose level. Physical activity and diet also play a major role in overall health. Working with a qualified professional will help you achieve your health and fitness goals.

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