What is a healthy BMI?

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

Is BMI accurate for athletes?

BMI doesn't account for muscle mass, so athletes may have high BMI despite being healthy.

What formula does the BMI Calculator use?

BMI = weight (kg) ÷ height² (m²). For imperial units: BMI = (weight in lbs × 703) ÷ height² (inches²). Both metric and imperial inputs are supported.

What are the WHO BMI categories?

Under 18.5: Underweight. 18.5–24.9: Normal weight. 25.0–29.9: Overweight. 30.0–34.9: Obese Class I. 35.0–39.9: Obese Class II. 40.0+: Obese Class III (severe obesity). These are World Health Organisation classifications.

Is BMI an accurate health indicator?

BMI is a useful population-level screening tool but does not account for muscle mass, bone density, age, sex, or fat distribution. Athletes may have high BMI with low body fat; older adults may have normal BMI with high body fat. Use it alongside other health assessments.

How accurate are the results from BMI Calculator?

BMI Calculator uses standard industry formulas to produce accurate estimates for planning purposes. Results are indicative only and should not substitute professional financial, tax, or legal advice. Consult a qualified advisor for specific decisions.

Does BMI Calculator save my inputs for future visits?

Your inputs are not sent to any server. Some browsers restore form values on page revisit via local session state, but we never store or transmit your financial figures.

Is BMI Calculator free to use?

Yes, BMI Calculator is 100% free with no usage limits, no watermarks, and no hidden charges. The platform is supported by non-intrusive advertising so all tools stay free for everyone.

Do I need to create an account to use BMI Calculator?

No account or registration is required. Open BMI Calculator and start immediately — no email, no sign-up, no personal information needed.

Is my data safe when using BMI Calculator?

Yes. BMI Calculator runs entirely in your browser using client-side JavaScript. Your files and data never leave your device and are never transmitted to our servers.

Does BMI Calculator work on mobile and tablet devices?

Yes. BMI Calculator is fully responsive and tested on smartphones, tablets, and all major desktop browsers (Chrome, Firefox, Safari, and Edge). The interface adapts automatically to any screen size.

BMI Calculator

Calculate your Body Mass Index

FreeNo sign-upCalculators →

BMI Calculator is a free, browser-based financial and mathematical calculations tool. Calculate your BMI (Body Mass Index) using weight and height. Supports metric (kg/cm) and imperial (lb/in) units. Includes healthy weight range.

Individuals, students, business owners, and financial planners use BMI Calculator every day to save time and skip the overhead of desktop software or paid services. No installation, no account, and no technical knowledge required — just enter your values into BMI Calculator and get results in seconds. Your files never leave your browser — full privacy by design.

kg / cm

Weight (kg)

Height (cm)

Enter your weight and height to calculate BMI

BMI Scale

Underweight

< 18.5

Normal

18.5–24.9

Overweight

25–29.9

Obese

≥ 30

How to use BMI Calculator

Enter weight

Enter your weight in kg or lbs.

Enter height

Enter your height in cm or feet/inches.

Calculate

Click calculate to get your BMI.

Interpret results

See your BMI category and healthy range.

Use Cases

Check if your weight is healthy
Track fitness progress over time
Calculate BMI for medical records
Understand healthy weight ranges

Key Benefits

100% free with no usage limits, watermarks, or hidden fees
No account or sign-up required — use it instantly
Works in all modern browsers on desktop, tablet, and mobile
Privacy-first: all processing runs locally, files never leave your device
Instant real-time results — updates as you type
Based on standard industry-accepted formulas
Results displayed clearly with full breakdown