BMI Calculator

What does my BMI number mean?

Your BMI is simply your weight-to-height ratio: Under 18.5 is underweight, from 18.5 to 24.9 is normal weight, from 25 to 29.9 is overweight and anything above 30 classifies as obese. These ranges are based on studies showing a correlation between a higher BMI and increased risks of health issues.

Is BMI accurate for athletes or muscular people?

Not really! Since BMI can't distinguish between muscle and fat, athletes often get labeled as overweight or obese when that is clearly not the case! The best way to find out if you're in a healthy range is by measuring your body fat percentage.

Is BMI different for men and women?

BMI is calculated the same way for men and women, but naturally women carry more body fat than men. A man and a woman who have the same BMI of 24 will have different body fat percentages. That is one of the limitations of BMI and why we recommend also doing other measurements such as the waist-to-height ratio.

What is a healthy BMI for someone over 65?

Some studies suggest that people over 65 might actually do better with higher BMI than the general adult population. A BMI of 25 to 27 is considered overweight but it might offer protection against illness and fractures as we age. If you're over 65, talk with your GP to see if your weight is right for you.

Why is BMI still used if it has so many limitations?

Well, it's free, quick and easy! All you need is a scale and a tape measure! More accurate methods like DEXA scans can be expensive or difficult to find. For large population studies BMI remains handy, but don't let it be the only metric you look at!

How often should I calculate my BMI?

There's no strict rule. Measuring your BMI every few months should be enough for most people. However, if you're actively working toward losing or gaining weight, tracking monthly alongside other measurements such as waist circumference can really help to monitor your progress.

Should I lose weight if my BMI is over 25?

Not necessarily. A person with a BMI between 25 and 30 who has a normal blood pressure, cholesterol and blood sugar level may not require weight loss, especially if they're already active. Fitness levels matter, so a person with a BMI of 26 can still be healthier than a sedentary person with a BMI of 23. Talk to your GP for advice specific to your situation.