BMI - Fitness Calculator
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BMI Calculator
Enter your weight and height to calculate your Body Mass Index (BMI).
Body Mass Index (BMI)
Formula
- Metric: BMI = weight_kg / (height_m)²
- US/Imperial: BMI = 703 * weight_lb / (height_in)²
Quick Conversions
- 1 ft = 12 in
- 1 in = 2.54 cm
- 1 m = 100 cm
- 1 kg ≈ 2.20462 lb
Examples
- US example: 180 lb, 5 ft 9 in (69 in)
BMI = 703 * 180 / (69²) = 126,540 / 4,761 ≈ 26.6 - Metric example: 72 kg, 1.75 m
BMI = 72 / (1.75²) = 72 / 3.0625 ≈ 23.5
Adult BMI Categories (kg/m²)
- Underweight: < 18.5
- Healthy weight: 18.5–24.9
- Overweight: 25.0–29.9
- Obesity (Class I): 30.0–34.9
- Obesity (Class II): 35.0–39.9
- Obesity (Class III): ≥ 40.0
Definitions
- Weight: Body mass (kg or lb)
- Height: Stature without shoes (m or in)
- BMI: Weight-to-height ratio used to screen weight categories (not a direct measure of body fat)
Notes / Limitations
- BMI is a screening tool, not a diagnostic of health.
- Can misclassify very muscular people, older adults with low muscle mass, and those who are pregnant.
- For children/teens, use age- and sex-specific BMI percentiles rather than the adult cutoffs.
Disclaimer
The information provided here is educational and not a substitute for professional medical advice, diagnosis, or treatment. Because health and lifestyle matter in a holistic approach, consult your physician with any questions.
Frequently Asked Questions
Are these calculators free to use?
Yes, all calculators on the site are completely free to use. You don’t need to sign up or provide any personal information.
How accurate are the results?
The calculators provide estimates only. They are based on the numbers you enter and standard formulas (such as compound interest or amortization schedules). Actual results may vary depending on factors like taxes, fees, or individual financial circumstances.
Can I use these calculators for financial planning?
The calculators are designed to help you explore scenarios and compare options. They are not a substitute for personalized financial advice. For a detailed plan tailored to your goals, we recommend scheduling a consultation.
Do the calculators account for taxes or inflation?
Most calculators do not automatically include taxes or inflation unless specifically stated. You can often adjust the interest rate or contribution assumptions to approximate these factors.
Do these calculators support different compounding periods?
Yes, some calculators allow you to choose how interest is compounded (monthly, quarterly, annually, etc.). This flexibility helps model real-world savings and investment scenarios more accurately.
What if my situation doesn’t fit the calculator exactly?
That’s common! These tools are meant to give you a baseline estimate. If your situation involves unique factors (tax rules, irregular cash flows, multiple accounts), schedule a conversation so we can customize the numbers.
Is my data saved or tracked?
No. All calculations run in your browser. We do not save or transmit your inputs.
