Daily Nutrition & Health
How to Calculate Your BMI and Achieve a Healthy Weight
Charlotte Lok, Member, Herbalife Dietetic Advisory Board, Singapore 24 July 2023
When people decide to change their habits and set a health goal, they often try to achieve a healthy weight, but let’s pause for a second and ask, what is a healthy weight? Is it a number? A feeling? Is there even a “right weight”? Each person’s body is unique, and a healthy weight depends on that person’s size, lifestyle and goals. For a more accurate determination of what a healthy weight is, use the Body Mass Index (BMI).
What Is Body Mass Index (BMI)?
Body Mass Index is a measure of body fat based on height and weight. It is used for adults and helps determine your risk for weight-related health issues. Once you calculate your BMI, you’ll be categorized into one of four health categories: underweight, normal, overweight and obese. It can also be influenced by age, gender and even ethnicity, especially for Asians.
Why Is Asian BMI Different?
It’s no secret that everyone’s genetic makeup is different. But when determining BMI, studies show that Asians, given the same body fat, age and gender, tend to have a lower BMI. Therefore, the BMI category ranges for Asians had to be lowered to account for the lower overall BMI.
In Asia, a BMI of over 23 is regarded as overweight (vs. 24.9 for other ethnicities) and a BMI of 27.5 (vs. 30) and above is considered obese. Overall, the Asian BMI is adjusted to be as accurate as possible and provides a quick check-in to see if your weight is healthy for your profile.
How to Calculate Your BMI
Weigh yourself in kilograms (or pounds) and divide that number by the square of your height in meters (or feet). Then, use that number to determine where you fit in the health categories: underweight, normal, overweight or obese.
Formula: kg/m2
How to Calculate BMI for Women
Calculating BMI for women uses the same formula (kg/m2) and weight category charts as men, but remember, BMI categories for Asians are different than other ethnicities, so double-check which BMI chart you’re looking at
What Is a Healthy BMI?
Based on your BMI calculation, you can determine your classification based on the chart below.
| BODY MASS INDEX (KG/M2) | CLASSIFICATION |
| Below 18.5 | Underweight (Risk of nutritional deficiency diseases) |
| 18.5 to 22.5 | Healthy weight (Low risk) |
| 23 to 27.9 | Overweight (Moderate risk) |
| Above 25 | Obese (High risk) |
Source: Adapted from Health Hub Singapore
Exceptions to the Rule: Is BMI Always Accurate?
BMI does not distinguish between fat and muscle. Therefore, those with higher-than-average muscle mass, like body builders and athletes, will have a higher weight and end up with a misleadingly high BMI value.
BMI may also be unsuitable for certain populations and individuals, including Aboriginal people, Pacific Islanders, children, pregnant women and the elderly.
Because of these limitations, consider BMI as a quick and simple measurement of your body fat. It’s a broad guideline for determining if you’re at a healthy weight. Use it in conjunction with other body-weight indicators to get a more accurate depiction of your healthy weight calculation.
BMI Versus Waist Circumference
Measuring your waist circumference is a great predictor of your health. No matter what your height or build is, an increased waistline can be a sign that your health is more at risk.
The calculations on this site are estimates, and content is provided for general information only. It should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. Always consult your own general practitioner if you’re in any way concerned about your health.
How to Maintain a Healthy BMI
Good news: Achieving and maintaining a healthy BMI doesn’t require a drastic change from living a modest healthy, active lifestyle. The first step is to ensure you’re eating balanced meals with good sources of protein and vegetables – fish and leafy greens are a “Yes!” while high-calorie, high-sugar foods like deep-fried chicken or pastries are a “In moderation!”
Also keep an eye on your portion sizes and, of course, move your body. Even a light, daily 20-minute walk can pay huge health dividends. When it comes down to it, a well-balanced diet full of good nutrition combined with an active lifestyle can help keep you in a healthy weight and healthy BMI.
Calculating your Body Mass Index is one quick, simple measuring tool to help you reach a healthy weight and stay there.