Calculating BMI usually means looking up a formula or using a health app. The BMI Calculator does it in the browser: enter height and weight (metric or imperial) and get your BMI and weight category—no sign-up and no data sent to a server.
What is a healthy BMI?
A healthy BMI is generally between 18.5 and 24.9. Below 18.5 is underweight, above 25 is overweight. BMI is a general indicator and may not be accurate for athletes, elderly, or pregnant women. The tool needs height (cm or ft/in) and weight (kg or lb); metric and imperial are supported. Calculation runs in your browser; your inputs are not stored or sent. Use it for a quick health snapshot or screening. It does not replace a doctor's assessment.
Key Features
- Metric and imperial — Height (cm or ft/in) and weight (kg or lb). Metric and imperial are supported.
- Category — Underweight, normal, overweight, and related ranges. BMI does not account for muscle mass or body composition; athletes may show "overweight" despite being fit. Use as one of several indicators if your category seems wrong.
- Privacy — No. Your data is not sent to a server. Calculation runs in your browser. Your inputs are not stored or sent.
- No account — Use as often as you need without sign-up.
- Quick snapshot — Use for screening only. It does not replace a doctor's assessment.
How to Use the BMI Calculator
- Open the BMI Calculator tool.
- Enter height (cm or ft/in) and weight (kg or lb). View your BMI and category.
- Use the "Use tool" button on the docs page if you are reading this from the documentation.
Real Use Cases
- Quick health snapshot — Get BMI and category in seconds. Use as one input for wellness tracking.
- Screening — General indicator for weight-related risk. Follow up with a healthcare provider when needed.
- Fitness tracking — Track BMI over time (e.g. before/after). Remember it does not distinguish muscle from fat.
- Teaching — Demonstrate BMI formula and categories. Explain limitations (athletes, age, pregnancy).
- Research — Quick reference for population or survey data. Not a substitute for clinical assessment.
Why Use the BMI Calculator Instead of Alternatives?
- vs. Percentage Calculator — Percentage Calculator does percent math. This tool is for BMI only. Different purpose.
- vs. Age Calculator — Age Calculator calculates age. This tool calculates BMI. Use both as needed.
- vs. Unit Converter — Unit Converter converts units. This tool uses height/weight to compute BMI. Use unit converter if you need to convert lb to kg first.
- vs. Manual formula — No need to compute weight/height² by hand. Enter, view, copy.
BMI does not account for muscle mass or body composition. Athletes may show "overweight" despite being fit. Use as one of several indicators.
Benefits for Individuals, Educators, and Coaches
- Individuals — Quick check. Privacy-friendly; no data sent.
- Educators — Teach BMI and its limits. Metric and imperial.
- Coaches — Reference for screening; always recommend professional advice when needed.
Common Mistakes
- Category seems wrong — BMI does not account for muscle mass or body composition. Athletes may show "overweight" despite being fit. Use as one of several indicators.
- Wrong units — Double-check metric vs imperial. Mixing kg with ft/in gives wrong results.
- Replacing medical advice — Use for screening only. It does not replace a doctor's assessment.
- Forgetting to copy — The result is not saved. Copy or screenshot if needed.
Frequently Asked Questions
What is a healthy BMI?
A healthy BMI is generally between 18.5 and 24.9. Below 18.5 is underweight, above 25 is overweight.
Is BMI accurate for everyone?
BMI is a general indicator and may not be accurate for athletes, elderly, or pregnant women.
Height (cm or ft/in) and weight (kg or lb). Metric and imperial are supported.
Is my data sent to a server?
No. Calculation runs in your browser. Your inputs are not stored or sent.
When should I use a BMI calculator?
Use it for a quick health snapshot or screening. It does not replace a doctor's assessment.
Why does my category seem wrong?
BMI does not account for muscle mass or body composition. Athletes may show 'overweight' despite being fit. Use as one of several indicators.
BMI Calculator gives you BMI and category in seconds: enter height and weight, view result. No account, no server round-trip. For percentages use Percentage Calculator, for age use Age Calculator, and for units use Unit Converter.
Use the BMI Calculator tool to calculate BMI.