BMI Calculator​

Use our free online BMI Calculator to estimate your Body Mass Index in seconds. Enter your height and weight to find out whether your BMI falls into the underweight, healthy weight, overweight, or obesity category. This calculator is suitable for most adults and provides a quick starting point for understanding your overall health.

FREE BMI Calculator

Free BMI Calculator

Calculate BMI, BMR and Estimated Daily Calories.

What is BMI?

Body Mass Index (BMI) is a screening tool that estimates whether your weight is appropriate for your height. It is calculated using your height and weight and is commonly used to classify adults as underweight, healthy weight, overweight, or obese. Although BMI does not directly measure body fat, it is a quick way to assess weight-related health risks.

Although BMI does not directly measure body fat, it is considered one of the easiest screening tools for identifying potential health risks related to weight. Healthcare professionals around the world use BMI as an initial assessment before recommending further medical evaluations.

Body Mass Index (BMI) is widely used as a screening tool by healthcare professionals around the world. According to the World Health Organization (WHO), BMI is one of the standard methods used to classify weight status in adults.

How to Use This BMI Calculator

Using the BMI Calculator is simple and takes only a few seconds.

  1. Select your gender.
  2. Enter your age.
  3. Enter your height in centimeters.
  4. Enter your weight in kilograms.
  5. Choose your activity level.
  6. Click the Calculate button.
 

The calculator will instantly display:

  • Your BMI Score
  • BMI Category
  • Basal Metabolic Rate (BMR)
  • Estimated Daily Calorie Needs

BMI Formula

BMI is calculated using a simple mathematical formula:

BMI = Weight (kg) ÷ Height² (m²)

Example

If your weight is 70 kg and your height is 170 cm (1.70 m)

BMI = 70 ÷ (1.70 × 1.70)

BMI = 24.2

This falls within the Healthy Weight category.

BMI Categories Chart

Our BMI Categories Chart provides a simple way to interpret your BMI score after using the calculator. Once you calculate your Body Mass Index, compare your result with the chart below to identify your weight category. Understanding your BMI category can help you assess potential health risks and make informed decisions about your diet, exercise, and overall lifestyle. While BMI is a useful screening tool, it should be considered alongside other health indicators for a complete assessment.

BMI RangeWeight CategoryHealth Risk
Below 18.5UnderweightNutritional deficiencies
18.5–24.9Healthy WeightLow
25–29.9OverweightIncreased
30–34.9Obesity Class IHigh
35–39.9Obesity Class IIVery High
40+Obesity Class IIIExtremely High

The BMI categories used in this calculator are based on internationally recognized guidelines. You can also learn more from the Centers for Disease Control and Prevention (CDC).

Note: BMI categories are designed for adults and may not be suitable for children, pregnant women, athletes, or individuals with high muscle mass.

What Is a Healthy BMI?

A healthy BMI for most adults falls between 18.5 and 24.9. Maintaining a healthy BMI is associated with a lower risk of developing chronic conditions such as type 2 diabetes, high blood pressure, heart disease, and certain types of cancer.

However, BMI should always be interpreted alongside other health factors, including body composition, waist circumference, physical activity, and overall lifestyle.

Limitations of BMI

While BMI is a useful screening tool, it has several limitations.

It does not distinguish between muscle and body fat. Athletes or individuals with high muscle mass may have a higher BMI despite having low body fat. Similarly, older adults may have a normal BMI while carrying excess body fat.

BMI is also not designed for pregnant women, young children, or individuals with certain medical conditions.

For a complete assessment of your health, BMI should be used alongside other measurements such as waist circumference, body fat percentage, and professional medical advice.

Benefits of Maintaining a Healthy BMI

A healthy BMI for most adults falls between 18.5 and 24.9. Maintaining a healthy BMI is

Keeping your BMI within the healthy range offers several long-term health benefits:

  • Supports heart health
  • Reduces the risk of obesity-related diseases
  • Improves energy levels
  • Enhances physical performance
  • Supports healthy blood pressure
  • Improves mobility and joint health
  • Helps maintain balanced blood sugar levels

associated with a lower risk of developing chronic conditions such as type 2 diabetes, high blood pressure, heart disease, and certain types of cancer.

However, BMI should always be interpreted alongside other health factors, including body composition, waist circumference, physical activity, and overall lifestyle.

Tips to Maintain a Healthy BMI

Maintaining a healthy BMI involves consistent lifestyle habits rather than quick fixes.

  • Eat a balanced diet rich in vegetables, fruits, lean proteins, and whole grains.
  • Stay physically active with at least 150 minutes of moderate exercise each week.
  • Strength train at least twice per week to preserve muscle mass.
  • Get 7–9 hours of quality sleep each night.
  • Stay hydrated throughout the day.
  • Avoid excessive intake of sugary drinks and ultra-processed foods.

Frequently Asked Questions

Is BMI accurate?

BMI is a reliable screening tool for most adults, but it does not directly measure body fat or muscle mass.

What is a healthy BMI?

A BMI between 18.5 and 24.9 is considered healthy for most adults.

How often should I calculate my BMI?

Checking your BMI every few months is sufficient for most people unless you are actively working toward a weight-management goal.

Does age affect BMI?

The BMI formula remains the same for adults, but health interpretation may vary with age and individual circumstances.

Can athletes rely on BMI?

Athletes often have more muscle mass, which can increase BMI without indicating excess body fat.

What is an Online BMI Calculator?

An Online BMI Calculator is a free digital tool that helps you calculate your Body Mass Index (BMI) using your height and weight. It instantly estimates whether you fall into the underweight, healthy weight, overweight, or obesity category based on standard BMI guidelines. Our Online BMI Calculator also estimates your BMR and daily calorie needs, making it easier to understand your overall health and fitness goals.

How do you calculate your BMI?

You can calculate your BMI using the formula:

BMI = Weight (kg) ÷ Height² (m²)

For example, if you weigh 70 kg and your height is 170 cm (1.70 m):

BMI = 70 ÷ (1.70 × 1.70) = 24.2

If you don’t want to calculate it manually, simply use our Online BMI Calculator to get your BMI, BMR, and daily calorie estimate instantly.

What is 170 cm with 70 kg?

If your height is 170 cm and your weight is 70 kg, your BMI is approximately 24.2. This falls within the Healthy Weight category according to standard BMI classifications.

What is a good BMI for my age?

For most adults aged 18 years and older, a healthy BMI is between 18.5 and 24.9. While age can affect body composition, the standard BMI ranges remain the same for adults. Older adults, athletes, and pregnant women may need additional health measurements beyond BMI.

How many calories should I eat to maintain my BMI?

To maintain your current BMI, you should consume approximately the same number of calories that your body burns each day. This is known as your maintenance calories, which depend on your BMR and activity level.

What is BMR?

BMR (Basal Metabolic Rate) is the number of calories your body needs each day to perform basic functions such as breathing, blood circulation, and maintaining body temperature while at rest. Our BMI Calculator also estimates your BMR based on your age, gender, height, and weight.

What is the difference between BMI and BMR?

BMI (Body Mass Index) measures whether your weight is appropriate for your height, while BMR estimates the number of calories your body burns at rest. BMI helps assess your weight category, whereas BMR helps estimate your daily calorie needs. Our calculator provides both values to give you a better understanding of your health.

Why does this BMI Calculator show my BMR?

Our BMI Calculator includes a BMR estimate to provide more useful health insights. While BMI tells you your weight category, BMR helps estimate how many calories your body needs each day. Together, these values can support weight management, fitness, and nutrition planning.

Medical Disclaimer

This BMI Calculator is intended for educational purposes only and should not replace professional medical advice. BMI is a screening tool and should be interpreted alongside other health measurements and professional guidance.