BMI Calculator
A BMI calculator works out your body mass index — your weight in kilograms divided by the square of your height in metres — a standard screening number for weight categories. FreeToolsKit's calculator accepts metric or imperial units and shows which category your result falls in, plus the healthy weight range for your height. Your entries stay in your browser.
Last updated: October 20, 2026
BMI 22.9 — Healthy
Healthy weight range for your height: 56.7 kg – 76.3 kg. Your category range is 18.5 – 24.9.
BMI is a general guide used for screening, not medical advice and not a diagnosis. It does not measure body fat directly and can misclassify muscular people and older adults. For personal health questions, speak to a qualified medical professional.
Key takeaways
- BMI is calculated as kg ÷ m², or with imperial units as 703 × lb ÷ in².
- Categories follow the standard adult ranges: under 18.5 Underweight, 18.5–24.9 Healthy, 25–29.9 Overweight, 30 and above Obese.
- The calculator shows the healthy weight range that matches your height, not just a single number.
- BMI is a general screening guide, not a diagnosis — it does not measure body fat directly.
How do you calculate your BMI?
- Choose Metric (kilograms and centimetres) or Imperial (pounds, feet and inches).
- Enter your weight and your height.
- Read your BMI value and its category, shown on the gauge.
- Check the healthy weight range for your height under the result.
- Switch units any time — values convert without you re-measuring anything.
What is the BMI Calculator used for?
- A quick health check before setting a weight goal.
- Filling a form for sports, work or insurance that asks for BMI.
- Tracking whether a long-term weight change has moved your category.
- Understanding a number a doctor or fitness app quoted to you.
- Checking the healthy weight range for a teenager's height as they grow (adult ranges are a rough guide only).
Frequently asked questions
What is a healthy BMI?
For adults, a BMI between 18.5 and 24.9 is classified as healthy. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese. These are population screening ranges, not personal health verdicts.
Is BMI accurate for athletes and muscular people?
BMI can misclassify people with a lot of muscle, because it cannot tell muscle from fat — a muscular athlete may score “overweight” with low body fat. It is best used as one signal among several, alongside waist size, fitness and professional advice.
Does BMI apply to children?
Not directly. For children and teenagers BMI must be compared against age- and sex-specific growth percentiles. This calculator uses the adult ranges, so treat results for under-18s as indicative only and consult a clinician.
Is BMI medical advice?
No. BMI is a general guide used for screening; it does not diagnose any condition. If you are concerned about your weight or health, speak to a qualified medical professional — this tool simply does the arithmetic.
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