BMI Calculator: A complete guide on body mass index for 2024

The body mass index (BMI) is a simple measure that can help you determine whether you’re at a healthy weight or not. It divides your weight in kilograms by your height in meters squared, so it’s not surprising that the BMI calculator is one of the most commonly used health tools.

But how useful is it? And what does it mean if your BMI is too high? Read on for everything you need to know about this handy too.

What is BMI?

BMI is the most commonly used tool for measuring a person’s body fat. It can be calculated using a person’s height and weight, which makes it easy to measure.

The BMI formula is simple and is as follows: Weight in kilograms divided by height in meters squared (kg/m2).

For example, if you are 170 cms tall (1.7m) and your weight is 85 kgs, your BMI would be: 85 divided by 1.7 squared = 29.4. Therefore, your BMI is 29.4.

As you can see, it is easy to follow the BMI formula and calculate your own BMI with a simple calculator.

The US Centers for Disease Control and Prevention (CDC) has an interactive tool to help calculate your BMI. It uses the same BMI formula noted above. To use it, go to the BMI calculator. 

The BMI calculator is easy to use: You enter your height in feet or inches; then enter your weight in pounds or kilograms; and finally, click “Calculate.” The BMI calculator will automatically calculate your BMI and display a BMI chart with the results.

What is a normal BMI?

The first step is to use a BMI calculator using the BMI formula and calculate your BMI. The next step is to check it against a BMI chart. A BMI chart will have different ranges of BMI numbers and will show the ranges for healthy, overweight or obese.

If your BMI range falls in the BMI chart in the range of 18.5-24.9, you’re in the “normal” range. Your weight is not considered to be overweight or obese by the scientific community, but it can still affects your health in many ways.

Generally, having a standard BMI per the BMI chart means that you are at a healthy weight for your height and age. 

However, there are some exceptions: If you’re an athlete who exercises regularly or has an active lifestyle, you may have a higher-than-average muscle mass which can give you a high BMI and the appearance of being heavier than you are. The opposite can also happen, if you have little muscle mass and low body fat content (which would indicate being underweight), this could also cause someone to fall into this category when they shouldn’t necessarily be classified as “normal”.

If someone’s BMI is between the 25-29 range in the BMI chart, they are considered overweight; if their BMI goes above 30, they fall within obesity territory.

Here is a BMI chart based on WHO guidelines:

If your BMI as per a BMI calculator is 25 or above, then it indicates that you are in the overweight range and should look to reduce your BMI within the healthy range. Similarly, if your BMI as per a BMI calculator is 30 or above, then it indicates that you are in the obese range and should look to reduce your BMI towards the healthy range.

 BMI chart for South Asians and Indians is different

While the BMI formula is the same for everyone, the BMI chart to use is different for people of South Asian descent. The reason for this is that studies have shown that South Asians are more susceptible to the adverse effects of being overweight, including type 2 diabetes and heart disease at lower BMIs.

Refer to the below BMI chart for South Asians and Indians. Remember that the BMI formula remains the same as what we’ve discussed earlier.

If your BMI as per a BMI calculator is 23 or above, then it indicates that you are in the overweight range and should look to reduce your BMI within the healthy range. Similarly, if your BMI as per a BMI calculator is 25 or above, then it indicates that you are in the obese range and should look to reduce your BMI towards the healthy range.

Also Read: The Hidden Dangers Of Excessive Body Fat

What are the health risks if your BMI is too high?

Having a high BMI is associated with high blood pressure, high cholesterol and diabetes. All of these conditions can lead to heart disease and stroke. High BMI is also linked to some cancers, especially breast cancer. As your waist measurement increases, the risk of developing type 2 diabetes also increases significantly.

You may have sleep apnea if your BMI is 35 or greater; this condition causes you to stop breathing for short periods during sleep because you have too much fat in the neck area to allow it to expand during inhalation. This condition can be treated through lifestyle changes such as losing weight (if overweight) and increasing physical activity levels.

Obese people are more likely to develop a wide range of illnesses and ailments, including the following:

• Blood pressure problems (hypertension)
• Low HDL cholesterol, high LDL cholesterol, or high levels of triglycerides (dyslipidemia)
• Coronary heart disease
• Type 2 diabetes
• Stroke
• Gallbladder disease
• Arthritis in the hands and feet (a breakdown of cartilage and bone within a joint)
• Breathing issues and sleep apnea
• Chronic inflammation and increased oxidative stress
• Some cancers (breast, endometrial, kidney, colon, liver, and gallbladder)
• Low quality of life
• Mental diseases like severe anxiety, depression, and other mental disorders
•   Pain in the body and trouble with physical function

How useful is the Body Mass Index (BMI) calculator?

BMI is valuable in many ways given its simplicity and how easy the BMI formula is to use and interpret for most people. For example, it can be used as an easy screening tool to identify people who may be at risk for obesity-related health problems and then motivate those individuals to make healthier choices about nutrition and physical activity that lead to weight loss (or maintenance) over time. It also helps researchers track the prevalence of obesity in populations so they can better understand how prevention efforts are working (or not).

A BMI calculator can give an accurate picture of whether someone is overweight or obese. One study found that people whose BMIs were at least 30 had nearly double the risk of dying over six years compared with people with BMIs below 25.

A BMI calculator is a good starting point and an indicator of whether or not you’re overweight. However, it’s not perfect.

As the BMI formula is purely based on height and weight, it does not account for muscle mass, which can make it appear that you’re overweight if you have a lot of muscle mass. On the other hand, if all your weight comes from fat instead of muscle – as tends to be the case in older adults and sedentary people – BMI can underestimate your body fat content because it ignores how much fat is around your organs (visceral fat).

Should we stop giving so much “Weight” to BMI?

The simple answer is yes. 

We have seen that the BMI formula is purely based on height and weight. BMI doesn’t consider important factors like fitness level, genetics, and body fat distribution. Think of a BMI calculator more as a starting point.

There are other better measures to track your health, such as:

• Waist-to-height ratio (WHR) where waist circumference is related to height rather than total weight. Because the WHR calculation considers central or belly fat, it is more accurate than BMI. This is because for most people, fat gathers more around the internal organs in your stomach and such belly fat has been directly connected to diseases like heart disease and diabetes. With WHR, the aim is to keep it at 0.5 or less. So your waist measurement should be less than half your height.
  
• Resting heart rate (RHR) Heart beats per minute (BPM) is a fantastic indicator of how healthy and effective your cardiovascular system is; the higher your BPM, the lower your risk for heart disease and other disorders of a similar nature. If possible, attempt to determine your heart rate as soon as you wake up in the morning, before you get out of bed. Your resting heart rate is your body’s BPM when it is entirely at rest. Your pulse can be taken by placing your index and middle fingers on your neck or wrist, counting the beats for thirty seconds, and multiplying the result by two to determine your BPM. RHR typically ranges between 60 and 100 beats per minute, although it can fall as low as 40 beats in highly fit individuals. Your RHR will typically be lower the healthier you are.
  
• Waist-to-hip ratio. This ratio is obtained by dividing the waist measurement by the hip circumference using the same units of measurements for both. The hip is measured using a measuring tape at the point that gives the maximum diameter over the buttocks. So measure it at the widest point of your hips. The ratio measures how much fat is stored on your waist, hips, and buttocks. As we have seen with the WHR, not all excess weight is the same when it comes to your health risks. People who carry more of their weight around their midsection, may be at a higher risk of heart disease, type 2 diabetes than people who carry more of their weight in their hips and thighs. So knowing your waist-to-hip ratio is helpful.

Conclusion

There’s no denying that BMI is flawed as it’s too simplistic and the BMI formula only considers height and weight. But due to its ease of use, it remains an essential tool in the fight against obesity. A BMI calculator is a simple way to take stock of your health and identify whether or not you should make some lifestyle changes.

If you have concerns about your own BMI and want help with bringing it to a healthy range, we can help with our scientific and easy-to-follow weight loss program. You will track measures like your WHR in the Daily9 program and work towards bringing it to a healthy range through simple and sustainable changes to your diet.

About the Author

Coach Kannan

Kannan is a Precision Nutrition & ISSA Certified Nutrition Coach and a ACE-Certified Behavior Change Specialist. Kannan focuses on ideas that are scientific and also work in the real world. He is allergic to advice that is unscientific or not practical.