Health & Fitness
BMI Calculator
BMI — it computes Body Mass Index as weight (kg) ÷ height (m)², then maps it to the standard WHO category bands. This page runs that same calculation on your numbers, in your browser: no signup, no uploads, nothing stored.
BMI Calculator helps you work out your BMI. Enter your weight and height and it returns your BMI and weight category instantly, right in your browser with nothing uploaded.
About this calculator
It computes Body Mass Index as weight (kg) ÷ height (m)², then maps it to the standard WHO category bands. That is the whole of the calculation — the mistakes happen in the inputs. It matters when you want a quick screening number before deciding whether a habit, plan or measurement deserves a closer look. Worked example: For someone 1.75 m tall weighing 70 kg, BMI is weight divided by height squared: 70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 = 22.9 . Use the calculator with your own figures; it runs entirely on your device.
How to use
- Enter your weight in kilograms.
- Add your height in centimetres.
- Press Calculate to see your BMI value.
- Read the category and remember BMI is only a rough screen.
Why use BMI Calculator
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Educational
Uses common estimation formulas for educational purposes. Results are not medical advice and should not replace professional guidance.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Clear about formulas used and their limits, with disclaimers where they matter.
Common uses
BMI in personal-training sessions
Use it for staying accountable
Use it when learning what a metric means
BMI as a general wellness guide
Use it for setting realistic training goals
Use it when adjusting diet and exercise
Technical notes
BMI is weight in kilograms divided by height in metres squared. Categories use the unrounded value; a displayed rounded BMI may appear at a category boundary. This form applies standard adult categories and does not assess children, pregnancy or individual clinical circumstances. The weight examples correspond to BMI 18.5 and 24.9 and are not personal targets.
These are general-population estimates and not a substitute for advice from a qualified clinician.
The tool works offline once loaded, since every computation is client-side.
Worked example
For someone 1.75 m tall weighing 70 kg, BMI is weight divided by height squared: 70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 = 22.9. That sits within the commonly cited 18.5–24.9 'normal' band.
FAQ
How is BMI calculated?
BMI equals your weight in kilograms divided by your height in metres squared. For example, 70 kg at 1.75 m gives 70 / (1.75 × 1.75) ≈ 22.86.
What BMI range is considered normal?
For adults aged 20 and older, the standard categories are BMI below 18.5 for underweight, 18.5 to less than 25 for healthy weight, 25 to less than 30 for overweight, and 30 or above for obesity. Children and teens require age- and sex-specific interpretation.
What does BMI miss?
BMI does not distinguish muscle from fat or show where fat is stored, so athletes can read as overweight and some people with normal BMI can still carry excess fat.
Does the BMI Calculator send my data to a server?
No. The BMI Calculator runs entirely in your browser — your inputs never leave your device, and nothing is uploaded or stored.