BMI Calculator

The BMI Calculator helps you calculate your Body Mass Index (BMI) using either metric or imperial units. Simply enter your height and weight to instantly see your BMI score and the weight category it falls into. BMI is a widely used screening tool that provides a general indication of whether your weight is appropriate for your height.

While BMI is useful for identifying potential weight-related health risks, it does not measure body fat directly and should not be used as the sole indicator of your overall health.

Disclaimer: BMI is a general guide only and does not account for muscle mass, bone density, body composition, age, gender, or ethnicity. Always consult a qualified healthcare professional for a personalised health assessment.

Why Use a BMI Calculator?

Maintaining a healthy weight is an important part of overall well-being. A BMI Calculator provides a quick way to assess whether your weight falls within a generally accepted healthy range based on your height.

Many healthcare providers use BMI as an initial screening tool to identify individuals who may benefit from further health assessments. Although it has limitations, BMI remains one of the simplest and most widely recognised methods for evaluating weight status.

Features

• Calculate BMI instantly
• Supports both metric and imperial units
• Displays your BMI score
• Shows your BMI weight category
• Easy-to-use interface
• Works on desktop, tablet, and mobile devices
• No downloads or registration required

How To Use the BMI Calculator

• Select your preferred measurement system (Metric or Imperial).
• Enter your height.
• Enter your weight.
• Click Calculate BMI.
• View your BMI score and corresponding weight category.

How BMI Is Calculated

Body Mass Index compares your weight to your height using a simple mathematical formula.

Metric Formula

• BMI = Weight (kg) ÷ Height² (m²)

Imperial Formula

• BMI = (Weight (lb) × 703) ÷ Height² (in²)

The calculator performs these calculations automatically, so there's no need to work them out manually.

BMI Categories

Adults are generally classified into the following BMI ranges:

• Below 18.5: Underweight
• 18.5 – 24.9: Healthy Weight
• 25.0 – 29.9: Overweight
• 30.0 and above: Obesity

These categories are intended as general screening guidelines and may not be appropriate for everyone.

Calculation Examples

Example 1 – Metric Units

• Height: 1.75 m
• Weight: 70 kg
• BMI = 22.9
• Category: Healthy Weight

Example 2 – Imperial Units

• Height: 5 ft 10 in
• Weight: 180 lb
• BMI = 25.8
• Category: Overweight

Example 3 – Weight Loss Goal

• Current Height: 1.80 m
• Current Weight: 95 kg
• Current BMI = 29.3
• If weight decreases to 80 kg:
• New BMI = 24.7
• Category changes from Overweight to Healthy Weight.

Common Uses

The BMI Calculator is commonly used to:

• Monitor body weight
• Track fitness progress
• Set weight management goals
• Support healthy lifestyle planning
• Estimate weight categories
• Prepare for medical check-ups
• Support nutrition and wellness programmes
• Monitor long-term weight changes

Understanding BMI

BMI is a useful screening tool, but it does not tell the whole story about a person's health.

For example:

• Athletes with high muscle mass may have a high BMI despite having low body fat.
• Older adults may have a healthy BMI but lower muscle mass.
• Children and teenagers require age-specific BMI calculations rather than adult BMI categories.
• Pregnancy and certain medical conditions can also affect how BMI should be interpreted.

For a more complete health assessment, healthcare professionals may also consider waist circumference, body fat percentage, blood pressure, cholesterol levels, physical activity, diet, and medical history.

Tips for Better Results

• Measure your height without shoes for the most accurate result.
• Weigh yourself at a consistent time of day, preferably in the morning.
• Use the same units throughout your calculation.
• Track your BMI over time rather than focusing on a single measurement.
• Remember that BMI is only one indicator of health and should be considered alongside other health measures.

Frequently Asked Questions

What is BMI?

BMI (Body Mass Index) is a numerical value calculated from your height and weight. It provides a general indication of whether your weight is appropriate for your height.

Is BMI accurate?

BMI is useful as a general screening tool, but it does not measure body fat directly or account for muscle mass, bone density, age, gender, or body composition.

What is considered a healthy BMI?

For most adults, a BMI between 18.5 and 24.9 is considered to fall within the healthy weight range.

Can athletes have a high BMI?

Yes. People with significant muscle mass often have a higher BMI even though they have low body fat. In these cases, BMI may overestimate body fatness.

Does BMI apply to children?

Children and teenagers use age- and sex-specific BMI percentiles rather than the standard adult BMI categories.

Can I use this calculator for weight loss?

Yes. Many people use BMI as one way to monitor their progress, although it should not be the only measure of health or fitness.

Is my information stored?

No. Your height and weight are processed in your browser and are not saved or shared.

Is the BMI Calculator free?

Yes. You can calculate your Body Mass Index online for free without creating an account or downloading software.