BMI Calculator
WEBCheck your body mass index and healthy weight category in metric or imperial.
A healthy BMI sits between 18.5–24.9. This is a general guide, not medical advice.
What it does
Carbide's BMI Calculator works out your body mass index from your height and weight and tells you which health category you fall into — underweight, normal weight, overweight, or obese — using the standard WHO scale. You can work in metric (centimetres and kilograms) or imperial (feet, inches and pounds): just flip the toggle and enter your measurements. The result includes a visual gauge showing where your BMI sits on the scale, so the reading is immediately clear. This tool is completely free, requires no sign-up, runs fully offline in your browser, and keeps all your health data on your device — nothing is uploaded or shared. It's a quick, informative starting point before a health check or medical conversation, not a replacement for professional advice.
How to use the BMI Calculator
- Open the BMI Calculator in Carbide.
- Choose your preferred unit system: Metric (cm / kg) or Imperial (ft, in / lb) using the toggle at the top.
- Drag the height slider (or type your height) to set your height.
- Drag the weight slider (or type your weight) to set your weight.
- Read your BMI value and category instantly — the gauge shows where you sit on the scale.
Frequently asked questions
- What BMI categories does it use?
- It uses the standard WHO categories: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), and Obese (30 and above).
- Can I use feet and inches instead of centimetres?
- Yes. Tap the Imperial toggle at the top of the tool and the inputs switch to feet/inches for height and pounds for weight. Your BMI is calculated correctly either way.
- Is my height and weight data stored or sent anywhere?
- No. Everything you enter stays in your browser session only. Nothing is saved to a server, database, or any external service.
- Is BMI a reliable indicator of health?
- BMI is a widely used screening tool, but it's not a complete health assessment — it doesn't account for muscle mass, age, or body fat distribution. Use it as a guide and speak to a healthcare professional for a full picture.