BMI is a general screening measure based on height and weight only — it doesn't account for muscle mass, bone density, age, or body composition. It's not a diagnosis. For a full picture of your health, talk with a doctor or other qualified healthcare provider.
About Caliper
Caliper calculates Body Mass Index from your height and weight, using either metric or imperial units, and shows where it falls on the standard BMI scale. Nothing you enter is uploaded or sent to a server.
Features
- Metric (kg/cm) or imperial (lb/ft-in) units
- Live calculation as you type
- Visual gauge showing where your BMI falls on the scale
- Standard WHO/CDC category labels
- No data stored — recalculates from scratch each visit
- Runs entirely in your browser — nothing is uploaded
How to use it
- Choose metric or imperial units.
- Enter your height and weight.
- Your BMI and category appear automatically, along with a gauge showing where it falls on the scale.
BMI category reference
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25 – 29.9 | Overweight |
| 30 and above | Obesity |
Frequently asked questions
How is BMI calculated?
BMI is weight in kilograms divided by height in meters squared. This tool handles the unit conversion for you if you enter imperial measurements.
Is BMI an accurate measure of health?
It's a widely used screening tool, but it has real limitations — it doesn't distinguish muscle from fat, and it can be less accurate for athletes, older adults, and some other groups. It's a starting point for a conversation with a healthcare provider, not a standalone diagnosis.
Does this account for age or sex?
No — this uses the standard adult BMI formula and category thresholds, which don't adjust for age or sex. Children and teens are assessed differently, using growth charts rather than fixed BMI categories.
Is my data sent anywhere?
No. All calculations happen locally in your browser using plain JavaScript — nothing is uploaded to a server.