BMI Basics: How to Read Your Body Mass Index

Ever see a number like 22.5 on a health form and wonder what it really means? That’s your Body Mass Index, or BMI. It’s a quick way to compare your height and weight and see if you fall into a healthy range. The good thing is you can figure it out in seconds with a calculator or an app. The downside? It’s not perfect, but it’s a handy starting point.

Understanding BMI Categories

When you plug your numbers into the formula, you get a result that lands in one of four categories:

• Underweight: BMI below 18.5. You might need more calories or a check‑up to rule out health issues.
• Normal weight: BMI 18.5 – 24.9. This range is linked to lower risk of heart disease, diabetes, and other problems.
• Overweight: BMI 25 – 29.9. You could benefit from small lifestyle tweaks like extra steps or smarter snacks.
• Obesity: BMI 30 and above. This signals a higher chance of chronic conditions, so a deeper look with a doctor is wise.

These cut‑offs are the same worldwide, so you’ll see them on most health sites, including the articles on this page.

How to Calculate and Interpret Your BMI

The math is simple: divide your weight in kilograms by the square of your height in meters. If you use pounds and inches, multiply your weight by 703 first, then divide by height squared. For example, a 150‑lb person who is 5'6" (66 inches) gets a BMI of about 24.2, landing squarely in the normal range.

Once you have your number, think of it as a flag, not a verdict. Muscular people can score high even if their body fat is low, and older adults might have a normal BMI but still carry excess fat around the waist. That’s why waist circumference, diet quality, and activity level matter too.

Here are three quick steps to use your BMI wisely:

1. Check the number: Know which category you’re in.
2. Look at the picture: Combine BMI with how you feel, your energy, and any medical advice.
3. Take action: If you’re out of the normal range, small changes—like adding a 20‑minute walk or swapping sugary drinks for water—can move the needle.

Our site’s collection of articles covers topics that intersect with BMI, from diabetes meds like Metformin to heart‑healthy supplements. Reading those pieces can give you a broader view of how weight, medication, and lifestyle all fit together.

Bottom line: BMI is a useful snapshot, not the whole story. Use it to spark a conversation with your doctor, track trends over time, and motivate realistic tweaks to your daily routine. Stay curious, keep moving, and let the numbers guide you toward better health.