BMI Calculator
Get your body mass index and see the healthy weight range for your height — metric or imperial, instantly.
- No upload
- Free
- No signup
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Your BMI
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- Healthy weight range for your height—
- BMI categories<18.5 under · 18.5–24.9 normal · 25–29.9 over · 30+ obese
Runs entirely in your browser. BMI is a general screening tool, not a diagnosis.
Generated entirely in your browser.
How to use BMI Calculator
- Pick your units — metric (cm / kg) or imperial (ft, in / lb).
- Enter your height and weight.
- Read your BMI number and its category — underweight, normal, overweight or obese.
- Check the healthy weight range shown for your height to see where you stand.
Common use cases
- Quick health check. Get a fast, standard screening number to see whether your weight sits in the healthy range for your height.
- Setting a weight goal. Use the healthy weight range for your height as a target band when planning to lose or gain weight.
- Tracking over time. Recalculate every few weeks to see how diet and exercise are moving your BMI toward the healthy range.
- Pairing with calorie planning. Combine your BMI with the calorie/TDEE calculator to build a realistic plan for reaching a healthy weight.
Tips
- BMI is a screening tool, not a diagnosis. It doesn't distinguish muscle from fat, so very muscular people can read as 'overweight'.
- The WHO categories are: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese.
- BMI is less accurate for the elderly, athletes, pregnant people and children. Talk to a doctor for a full picture.
- Waist circumference and body-fat percentage add useful context that BMI alone can't give.
Troubleshooting
- My BMI says overweight but I'm very fit.
- BMI can't tell muscle from fat. Athletes with high muscle mass often read high. Consider body-fat percentage or waist measurements for a fuller picture.
- The number changes a lot with small height edits.
- BMI depends on height squared, so height has a big effect. Double-check you entered your height correctly in the selected units.
Frequently asked questions
- How is BMI calculated?
- BMI is your weight in kilograms divided by your height in metres squared. This tool converts imperial units for you, so you can enter feet/inches and pounds.
- What is a healthy BMI?
- The WHO considers 18.5 to 24.9 a normal, healthy range. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or more is obese.
- Is BMI accurate for everyone?
- No. BMI is a general screening tool and can be misleading for athletes, the elderly, pregnant people and children because it doesn't measure body composition.
- What's my ideal weight?
- There's no single ideal, but the tool shows the weight range that corresponds to a normal BMI (18.5–24.9) for your height as a healthy target band.
- Is my health data private?
- Yes. Your height and weight never leave your device — the calculation runs entirely in your browser.