BMI Calculator not working? Here's how to fix it
Most issues with the BMI Calculator are small and fixable in seconds. Work through these in order.
1. The result looks far too high or low
The most common cause is using the wrong units. If you entered your weight in pounds but the unit is set to metric, the number will be wildly wrong. Switch to imperial or convert your inputs so the units match what you typed.
2. The BMI category seems wrong
Double-check your height value. A common mistake is entering height in meters as "175" instead of "1.75" — off by a factor of 100. Verify you typed the correct number of meters (or feet and inches).
3. The compute button does nothing
Make sure both height and weight fields have values. If either field is empty or contains a non-numeric character, the calculator won't run. Clear and re-enter valid numbers.
4. The healthy range looks off for your body type
BMI is a screening tool, not a measure of body fat. If you are very muscular or athletic, your BMI may read high despite low body fat. Use the category as guidance, not a diagnosis.
5. The tool won't load at all
Reload the page or open it in a fresh tab. If an extension blocks scripts, try private (incognito) mode — the calculator needs JavaScript, which is on by default in every modern browser.
Still stuck?
Try a different current browser (Chrome, Firefox, Safari, Edge). The tool behaves the same everywhere, so a fresh environment usually resolves the last edge cases.
Verdict
Most problems with BMI Calculator are solved by checking your units, correcting your height, or reloading the page.