What's a Healthy BMI?

What is a normal body mass index, or BMI, and why should you care? One should care about how much they weigh, as well as the amount of body mass and body fat they're carrying for a few different reasons.

Not only is it important to be at a healthy weight in terms of your overall health, but being either underweight, overweight, or obese can carry with that a lot of complications that can compromise your health and well-being.

You'll learn about a few reasons why you should closely monitor your body weight and BMI, as well as why doing so can reduce the risks of you needing to deal with such issues as cardiovascular disease, high cholesterol. or high blood pressure in the future. 

Related: How Do BMI Scales Work?

What Is Normal BMI?

Your body mass index, or BMI, is measured when your healthcare provider converts both your height and weight into what are called metric units. For every meter of the surface area of your body, your doctor will calculate the amount of weight that corresponds with it. This measurement calculates the unique composition of the amount of body fat that you're carrying. 

What exactly is a normal BMI? That largely depends on a person's weight. The standard body mass index chart tells healthy adults the weight range they should expect if they're at a certain height. Here are the ranges for the average adult of good health:

BMI Ranges:

  • Under 18: Underweight
  • 18 - 25: Normal
  • 25 - 30: Overweight
  • 30 - 40: Obese
  • Above 40: Morbidly obese

Why Do We Use BMI?

While measuring your body mass index to look for an increased risk for certain health conditions like Type 2 diabetes, hypertension, or heart disease isn't a perfect solution for every single person, your BMI range is usually a good method when it comes to assessing patients for risk factors for certain conditions.

For example, if a patient needs to follow a weight loss and wellness plan to get healthier, measuring that person's total body fat is a good indicator of the next steps they will need to take to get to a healthier weight and body fat percentage. 


Factors that Affect BMI

One of the things to keep in mind when it comes to measuring your body mass index is that it measures the amount of excess weight you're carrying, as opposed to the amount of excess body fat you have on you. For example, you might not carry any excess weight on your body. You might have a healthy BMI for your body weight and height. But despite all of that, you could still carry an excessive amount of fat on you. 

Benefits of BMI

When you follow the medical advice of your physician and maintain a healthy weight and BMI, you'll experience less joint pain as you age.

You'll also have higher energy levels,  be able to better regulate your blood pressure, reduce your risk of having to deal with such conditions as diabetes, high cholesterol, and other health ailments, and you'll reduce your levels of blood sugar, your blood triglycerides, and many other indicators of oncoming illnesses. 

Downfalls of BMI

There are some categories of people who would present as having a high BMI, despite living an extremely healthy lifestyle. These would include athletes and body builders who carry a lot of muscle mass on them, extremely short and extremely tall people who don't have average bone structures due to their short or tall frames, and people of an average height and weight who carry excessive body fat on them.


Other people who might present with a high BMI despite being healthy include women and older adults. Many older adults tend to carry a lot more body fat than their younger counterparts. With women of all ages, metabolism differences can explain why they often carry more body fat than men. 

Risks Associated with High BMI

For those adults who do not engage in a lot of physical activity, having a really high body mass index can lead to a host of serious health complications down the road. For one thing, you can increase your risk of cardiovascular issues. That's because carrying excess weight causes your heart to have to work harder to function properly. A high BMI can also increase your risk of hypertension, type 2 diabetes, and even sleep apnea. 

Risks Associated with Low BMI

Some of the health risks that can come with having a BMI that is lower than 18 can include finding yourself with nutrient deficiencies, hormone issues, and a weaker immune system. Women with a low BMI may even find themselves being at a higher risk for osteoporosis, a bone health condition that mainly affects older women.

Body Fat vs Body Mass

In the recent past, the research on body fat and body fat percentage has drastically improved. For some people, body fat measurements may be a more accurate measure of their health profile than the body mass index. That's because your body fat percentage separates your fat from your muscle. While you can get some idea of your body fat percentage from your BMI, your body fat measurements provide a much better picture of that metric. 

Adult BMI Calculator

Weight and height guide chart

To get an accurate idea of your BMI, please refer to this weight and height guide chart. This chart will give you a good picture of a healthy BMI number for your particular height and weight profile.

If you consult this chart and don't get the numbers you want, don't panic. The next step is to seek out the advice of your primary care doctor. 

Measure your waist-to-height ratio

To get your own waist-to-height ratio, you will first need to get your waist measurements and divide the size of your weight by your height. If you divide your waist size by your height and get a number that is 0.5 or lower, the chances are good that you have a healthy weight.