Calculate Your BMI
Enter your height and weight to get your Body Mass Index and see where it falls on the standard category spectrum.
General information only — this isn't a diagnosis. Check with your doctor about what your result means for you.
BMI Calculator
Enter your height and weight below. Everything runs in your browser.
What this tool calculates
A quick estimate, not a diagnosis.
BMI score
Weight relative to height, using the standard formula.
Category
Where your score sits against the standard reference ranges.
Category spectrum
A visual marker showing exactly where your BMI lands.
Your BMI Result
General information, not a diagnosis.
BMI categories, formulas & use cases
How each category is calculated, who typically checks it, and where it's used in practice.
Underweight
BMI below 18.5
User case
Someone recovering from illness, or a person who has lost weight quickly, checks whether their weight has dropped below the typical range for their height.
How it's calculated
50 kg at 170 cm → 17.3 — Underweight
Who uses it
- Individuals tracking recovery
- Dietitians
- Primary care clinics
Applications
Nutrition follow-ups, general wellness checks, screening before a fitness plan.
Healthy Weight
BMI 18.5 – 24.9
User case
Someone maintaining their current weight uses this range as a general reassurance point during a routine health check.
How it's calculated
75 kg at 180 cm → 23.1 — Healthy weight
Who uses it
- General adult population
- Fitness-goal setters
- Annual check-up patients
Applications
Routine wellness tracking, maintenance goal-setting, general health screening.
Overweight
BMI 25.0 – 29.9
User case
Someone starting a new exercise or nutrition plan uses this range as a baseline number to track change against over time.
How it's calculated
72 kg at 165 cm → 26.4 — Overweight
Who uses it
- People starting a fitness plan
- Nutrition coaches
- Corporate wellness programs
Applications
Goal-setting for weight management, tracking progress, workplace wellness checks.
Obesity
BMI 30.0 and above
User case
Someone preparing for a doctor's visit checks their BMI beforehand so they can discuss it as one data point in that appointment.
How it's calculated
95 kg at 170 cm → 32.9 — Obesity range
Who uses it
- Patients ahead of a consultation
- Doctors as a screening reference
- Insurance and wellness programs
Applications
Pre-appointment screening, long-term health planning discussions with a clinician.
Metric & US Customary BMI
Same score, two unit systems
User case
Someone used to pounds and feet-inches wants the same standard BMI score without converting units by hand first.
How it's calculated
US: weight (lbs) ÷ height² (in²) × 703
Who uses it
- Users in the US, UK, or metric countries
- Anyone switching between unit systems
Applications
Cross-border health records, travel and relocation health forms, general convenience.
Ponderal Index
An alternative to BMI
User case
A very tall or very short person wants a second number, since BMI can read unusually high or low at the extremes of height.
How it's calculated
Uses the cube of height, not the square
Who uses it
- Very tall or short individuals
- Researchers comparing body proportions
Applications
A secondary reference point alongside BMI, used in some clinical and research settings.
Clear, simple, transparent
What this BMI calculator does, and what it doesn't — no fine print.
What this calculator does
- Calculates BMI from height and weight
- Supports metric and US customary units
- Shows the BMI category
- Places the result on the category spectrum
- Calculates the result in the browser
What this calculator does not do
- Does not diagnose medical conditions
- Does not measure body fat
- Does not distinguish muscle from fat
- Does not provide personalized medical advice
- Does not replace a healthcare professional
Understanding your BMI
What your result means, and the context worth keeping in mind when you read it.
A BMI result can help you
- Compare weight relative to height
- Understand which standard reference category your result falls into
- Track changes over time
- Have a useful starting point for a health conversation
A BMI result should be interpreted with context
- It doesn't measure body fat directly
- It doesn't account for muscle mass
- It doesn't describe overall health by itself
- Individual interpretation can vary
Helpful resources
A longer read, related tools, and where to go for personal advice.
BMI Guide
A complete guide to Body Mass Index
What BMI does and doesn't tell you, how the categories were set, and where the Ponderal Index fits in.
Frequently asked questions
Quick answers about using the calculator and understanding your result.
Understanding BMI
What are the standard BMI categories?
What does my BMI result mean?
Is BMI a medical diagnosis?
Why might BMI not fully represent my body composition?
Using & Troubleshooting
What can I calculate with this tool?
Which units are supported?
Is my data stored?
Why isn't my result showing?
Ready to check your BMI?
Check another BMI result or explore more calculation tools.