BMI Calculator | Check Your Body Mass Index

Calculate your BMI (Body Mass Index) from height and weight

Find out if you are a healthy weight and get your ideal weight range, waist-to-height risk...

When Should You Use This Calculator?

Tracking BMI changes over time to monitor health progress
Setting target weight goals based on desired BMI ranges
Comparing BMI across different time periods with historical data
Planning weight management strategies with persistent tracking

Key Features:

Advisory note for under-18 results instead of adult BMI categories
Optional waist-to-height ratio risk context
Goal BMI timeline projection from weekly change assumptions
Reverse mode: calculate target weight from a goal BMI

Frequently Asked Questions

What is a healthy BMI range?

For adults, BMI 18.5-24.9 is generally considered healthy. Under 18, BMI should be interpreted with pediatric percentile guidance rather than adult cutoffs.

Is BMI accurate for athletes?

BMI can overestimate body fat in muscular individuals since muscle weighs more than fat. Athletes may have a high BMI but low body fat. Consider using body fat percentage or waist circumference as additional measures.

How do I calculate my ideal weight?

Use Reverse mode to compute target weight from goal BMI. In normal mode, you can also set a goal BMI and weekly change assumption to estimate a timeline to target.

Why include waist-to-height ratio?

Waist-to-height ratio can add risk context that BMI alone may miss. A commonly used heuristic is to keep waist below half of height.

Can I export my BMI Calculator calculations?

Yes. In guest mode you can export your calculations to JSON. Signing in adds PDF and CSV export. Click the export button to download your results — useful for record-keeping, sharing, or importing into other tools.

Does this calculator save my history?

Yes. Your calculation history is saved automatically. As a guest you can keep up to 50 calculations per workspace on your device. Sign in for free to keep up to 100 per workspace and access them from any device.

Is this calculator free to use?

Yes. The BMI Calculator is free to use with no sign-up required. A free account adds more calculation history, multiple workspaces, and access to your saved data from any device.

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