AnyCalc

Health & Fitness

BMI Calculator

Calculate your Body Mass Index with height and weight

Reviewed: AnyCalc Editorial|2026-07-19|Editorial policy|About

What this calculator does

Body Mass Index (BMI) is a simple screening metric that estimates body fat based on your weight and height. The formula is BMI = weight (kg) / height (m)², or equivalently BMI = 703 × weight (lb) / height (in)² for imperial units. Health organizations including the WHO classify BMI into categories: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), and obese (30 and above). While BMI does not directly measure body fat percentage and cannot distinguish between muscle and fat mass, it remains one of the most widely used tools in clinical and public health settings for identifying potential weight-related health risks. Our BMI calculator lets you enter your weight and height in either metric or imperial units and instantly see your category along with a visual chart. It is especially useful during routine health checkups, when setting weight-loss goals, or when a healthcare provider asks for your BMI. Keep in mind that athletes, older adults, and pregnant women may need additional assessments beyond BMI alone.

How to use

  1. 01
    Enter your details
    Input your height and weight in metric or imperial units.
  2. 02
    Click Calculate
    Press the Calculate button to compute your BMI score.
  3. 03
    View your results
    See your BMI value, weight category, and healthy weight range for your height.

BMI Calculator FAQ

What is a healthy BMI range for adults?▾
A BMI between 18.5 and 24.9 is considered normal weight by the World Health Organization. Values below 18.5 indicate underweight, 25–29.9 indicates overweight, and 30 or above falls into the obese category. These ranges apply to adults aged 20 and older.
Is BMI accurate for muscular people?▾
BMI can overestimate body fat in people with high muscle mass, such as athletes and bodybuilders, because it cannot distinguish between muscle and fat tissue. If you have significant muscle mass, complementary measures like waist circumference or body fat percentage testing give a more complete picture.
How is BMI calculated?▾
BMI is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). In imperial units, multiply your weight in pounds by 703 and divide by height in inches squared. For example, a person weighing 70 kg at 1.75 m tall has a BMI of 70 / (1.75 × 1.75) = 22.9.
Does BMI apply to children and teenagers?▾
Children and teens use age- and sex-specific BMI percentile charts rather than the fixed adult categories. A pediatrician compares a child's BMI to others of the same age and sex, with the 85th–94th percentile classified as overweight and the 95th percentile and above as obese.
How often should I check my BMI?▾
For most adults, checking BMI once or twice a year during routine health checkups is sufficient. If you are actively trying to lose or gain weight, monthly tracking can help measure progress, but always combine BMI with other health indicators like blood pressure and waist circumference.

Interpret carefully

Outputs are decision-support estimates, not a substitute for professional judgment.

  • Treating BMI Calculator output as a final professional diagnosis, quote, or legal determination
  • Entering approximate values when the result is sensitive to units or precision
  • Applying the FAQ answer (“What is a healthy BMI range for adults?”) to a special case without checking assumptions

Next steps

  1. Double-check inputs against your source documents (labs, statements, specs, or notes).
  2. Confirm the method below matches your use case before you act on the number.
  3. For medical, financial, or production decisions, verify with a qualified professional.

Disclaimer: Results are informational only and do not constitute medical, financial, legal, or professional advice. Report issues: sublimernj@gmail.com

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