What is BMI (Body Mass Index)?

BMI is a screening measure calculated from your weight and height: BMI = weight(kg) ÷ height(m)^2.

What is a normal BMI?

For most adults, a BMI from 18.5 to 24.9 is commonly categorized as a healthy weight range.

Am I overweight if my BMI is 25?

For most adult BMI category systems, a BMI of 25.0 to 29.9 is categorized as overweight.

What BMI is considered obese?

For adults, a BMI of 30.0 or higher is commonly categorized as obesity.

Is BMI different for men and women?

BMI uses the same numeric cutoffs for most adults, but health risk can differ by body composition, ethnicity, and fat distribution.

Does BMI work for athletes?

BMI can misclassify muscular people as overweight. Consider waist measurements, body fat percentage, and clinician assessment for a fuller picture.

How do I find a healthy weight for my height?

A simple method is to compute the weight range that corresponds to a BMI of 18.5 to 24.9 for your height.

Is BMI accurate for teenagers and kids?

For ages 2–19, BMI should be interpreted using age- and sex-specific percentiles rather than adult cutoffs.

Free BMI Calculator — Check Your Body Mass Index & Healthy Weight Range

📝 Enter Your Details

BMI uses your height + weight. Sex/age are optional (used for tailored tips & reference notes).

Unit System

Biological Sex (optional)

BMI cutoffs are the same for most adults, but tips can differ by context.

Age (years, optional)

Note: Adult BMI categories are typically used for ages 20+.

Please enter a valid age (2–100).

Height (cm)

Please enter a valid height (80–250 cm).

Weight (kg)

Please enter a valid weight (20–400 kg).

Results & Insights

Your BMI updates live as you type.

👈 Enter your height and weight to calculate BMI

Required: height + weight. Optional: sex + age.

⚖️ Your BMI (Body Mass Index) Category: —

—kg/m²

BMI is a screening metric based on weight relative to height.

📊 Visual BMI Scale

Where your BMI sits on the standard underweight → obesity scale (adult cutoffs).

Marker: —

14 18.5 25 30 40+

Underweight< 18.5

Healthy weight18.5–24.9

Overweight25.0–29.9

Obesity≥ 30.0

🎯 Healthy Weight Range for Your Height

—

This is the weight range corresponding to a BMI of 18.5–24.9 for your height.

🌍 Quick Global Context (Reference)

A simple reference comparison using global adult mean BMI (sex-specific). This is context, not a diagnosis.

Your BMI —

World mean BMI (adults, sex-specific) —

Difference —

Age note: Adult BMI cutoffs are commonly used for ages 20+. For children/teens, BMI percentiles are used instead.

💡 Personalized Recommendations

Actionable, high-trust guidance based on your BMI category + best-practice screening principles.

BMI: —

⚠️ Disclaimer (please read): BMI is a screening measure and does not directly measure body fat or health. It may be misleading for muscular individuals, pregnancy, certain medical conditions, or different ethnic risk profiles. If you're concerned about your weight, blood pressure, cholesterol, blood sugar, or waist circumference — consult a qualified clinician.

📌 Professional note

Know your BMI — then use it intelligently

BMI is one of the fastest screening tools in health, but it's not the full story. This calculator is designed to be "best-in-class" in 2026: clear category feedback, healthy weight range for your height, a visual scale, and practical next steps — without fear-mongering.

What Is a BMI Calculator?

A BMI calculator estimates your Body Mass Index using your height and weight. BMI is defined as weight relative to height (kg/m²). It's widely used as a quick screening measure to categorize body weight status in adults.

How to Use This BMI Calculator

Choose Metric or Imperial: Use whichever is easiest.
Enter height + weight: These two inputs are required.
(Optional) Enter age + sex: Used for extra context notes and tailored recommendations.
Read your results: BMI number, category, healthy weight range, visual scale, and recommended next steps.

How BMI Is Calculated (Formula)

1) The BMI equation

BMI = weight(kg) ÷ height(m)²

If you use imperial units (lbs + ft/in), this tool converts your inputs into metric behind the scenes for accurate math.

2) Healthy weight range

A "healthy weight range" is the body weight interval that corresponds to a BMI between 18.5 and 24.9 for your height. This calculator shows that range in kg or lbs depending on your unit system.

BMI Categories (Adults)

Category	BMI range (kg/m²)	What it means (simple)
Underweight	< 18.5	Below typical adult healthy range
Healthy weight	18.5–24.9	Typical adult healthy range
Overweight	25.0–29.9	Above typical adult healthy range
Obesity	≥ 30.0	Higher health-risk screening category

Important: BMI is a screening tool — interpret with other measures (waist, labs, fitness, medical history).

Frequently Asked Questions (BMI)

BMI is a screening measure calculated from your height and weight. It helps classify weight status categories in adults.

For many adult category systems, 18.5–24.9 is considered a "healthy weight" BMI range.

In common adult BMI categories, 25.0–29.9 is categorized as overweight.

A BMI of 30.0 or higher is commonly categorized as obesity for adults.

The numeric cutoffs are generally the same for adults, but health risk can vary by body composition and fat distribution.

BMI may label muscular people as overweight. Consider waist circumference, body fat estimates, and clinician evaluation for better accuracy.

This calculator shows the weight interval that corresponds to a BMI of 18.5–24.9 for your height.

For ages 2–19, BMI should be interpreted using BMI-for-age percentiles, not adult cutoffs.

📝 Enter Your Details

Results & Insights

📊 Visual BMI Scale

💡 Personalized Recommendations

Know your BMI — then use it intelligently

What Is a BMI Calculator?

How to Use This BMI Calculator

How BMI Is Calculated (Formula)

1) The BMI equation

2) Healthy weight range

BMI Categories (Adults)

Explore More Free Health Calculators

Frequently Asked Questions (BMI)