Skip to content
Kordu Tools
Calculators Runs in browser Updated 30 Mar 2026

BMI Calculator

Calculate your Body Mass Index with metric or imperial units and see your BMI category instantly.

Your measurements

Your BMI

22.9

Normal

1018.5253040
UnderweightNormalOverweightObese
Healthy weight range56.7 - 76.3 kg

BMI is a general indicator and does not account for muscle mass, bone density, age, or sex. Consult a healthcare professional for personalised advice.
Loading rating…

How to use BMI Calculator

  1. Choose your unit system

    Select Metric (kg and cm) or Imperial (lbs and feet/inches) using the toggle at the top.

  2. Enter your weight

    Type your weight in kilograms or pounds depending on your chosen unit system.

  3. Enter your height

    Type your height in centimetres, or in feet and inches for imperial.

  4. Read your BMI

    Your BMI is calculated instantly with the numeric value, color-coded category, and a visual gauge showing your position on the scale.

  5. Check the healthy weight range

    See the healthy BMI weight range for your exact height displayed below the gauge.

BMI Calculator FAQ

How is BMI calculated?
BMI = weight (kg) ÷ height (m)². For imperial units, weight in pounds and height in inches are converted to metric first: BMI = (weight in lbs × 703) ÷ (height in inches)².

What are the BMI categories?
The standard WHO adult categories: Underweight = below 18.5, Normal weight = 18.5–24.9, Overweight = 25–29.9, Obese = 30 and above. Some scales further divide obesity into class I (30–34.9), class II (35–39.9), and class III (40+).

What is a healthy BMI?
A BMI between 18.5 and 24.9 is generally considered normal weight for adults. However, BMI is a screening tool only — consult a healthcare professional for a full assessment.

Is BMI accurate for athletes and muscular people?
No. BMI can overestimate body fat in muscular individuals because it does not distinguish between muscle and fat. An athlete with high muscle mass may show an overweight or obese BMI despite being in excellent health.

Is BMI accurate for older adults?
Less so. Older adults often have less muscle mass and more body fat than younger adults at the same BMI. A BMI at the higher end of the normal range may be more appropriate as people age.

Does BMI apply to children?
Standard adult BMI categories do not apply to children. Children and teenagers use BMI-for-age percentiles that account for normal growth patterns and differ by sex.

What are the limitations of BMI?
BMI ignores body composition, muscle mass, bone density, age, sex, and ethnicity. People of Asian descent may face higher health risks at lower BMI values. Athletes may be misclassified as overweight. Use it as one indicator alongside other measures.

What is the healthy weight range for my height?
The tool calculates this automatically. The healthy range is the weight range that produces a BMI of 18.5–24.9 for your exact height.

Is my data sent to a server?
No. All BMI calculations happen entirely in your browser. Your weight and height are never transmitted anywhere.

Background

Enter your weight and height in metric (kg and cm) or imperial (lbs and feet/inches) to calculate your BMI instantly. The result is displayed with a color-coded category — underweight (under 18.5), normal weight (18.5–24.9), overweight (25–29.9), or obese (30+) — along with a visual gauge showing exactly where you fall on the BMI scale. See the healthy weight range for your height so you know your target. Toggle between metric and imperial with one click. Limitations are clearly noted: BMI does not account for muscle mass, bone density, age, sex, or ethnicity, so it is a screening tool rather than a diagnostic measure. Adults, athletes, children, and the elderly may all get misleading readings. All calculations run locally in your browser with no data sent anywhere.

Related tools

Percentage Calculator

Calculate X% of Y, find what percentage X is of Y, or compute percentage increase and decrease. Results update as you type.

Tip Calculator

Calculate tips instantly with preset percentages, custom amounts, bill splitting, and rounding options.

Compound Interest Calculator

Project how your savings grow over time with compound interest, monthly contributions, and different compounding frequencies.

Recipe Scaler

Scale any recipe up or down. Paste ingredients, set your target serving count, and get adjusted amounts with smart unit simplification.

Statistics Calculator

Calculate mean, median, mode, standard deviation, variance, quartiles, skewness, kurtosis, and range from any dataset. Histogram included.

Learn more

calculators

BMI Calculator: How to Calculate and Understand Your Body Mass Index

Calculate your BMI instantly with our free online calculator. Learn what BMI means, its categories, limitations, and when to consult a doctor.

calculators

BMI Chart and Alternatives: Health Metrics That Matter

BMI misclassifies roughly 54 million Americans. Compare BMI to waist-to-hip ratio, body fat percentage, and four other metrics doctors actually use today.