Metric BMI Calculator
The Body Mass Index or BMI, measures the human body shape based on your weight (kg) and height (m).
How to Calculate BMI
With our free BMI Calculator, you can calculate your BMI easily in metric or imperial reading and check if you are in the healthy range. First you must know your weight and your height to determine your Body Mass Index (BMI). Enter your information into the fields below to calculate your BMI.
You can calculate your BMI manually using the metric system:
- Formula: weight (kg) / [height (m)]2
- Calculation: [weight (kg) / height (cm) / height (cm)] x 10,000 (round to one decimal place)
Example: Lily’s weight is 32.5 kg and her height is 109.2 cm. What is Lily’s BMI?
(32.5 kg / 109.2 / 109.2) x 10,000 = 27.3
What is body mass index (BMI)?
The body mass index (BMI) is a simple and the most commonly used index used to classify overweight and obesity. It is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2).
The World Health Organization (WHO) defines overweight as a BMI of ≥ 25 and a BMI of ≥ 30 for obesity. However, because at any given BMI, Asians, including Singaporeans, generally have a higher percentage of body fat than do Caucasians, the BMI cut- off levels for Singaporeans have been revised such that a BMI 23 kg/m2 or higher marks a moderate increase in risk while a BMI 27.5 kg/m2 or more represents high risk for diabetes and cardiovascular diseases.
BMIs under 20.0 and over 25.0 have been associated with higher all-cause mortality, increasing risk from the 20.0–25.0 range.
BMI Categories (WHO):
- Underweight = <18.5
- Normal weight = 18.5–24.9
- Overweight = 25–29.9
- Obesity = BMI of 30 or greater
BMI Calculator Asian (Singapore) vs BMI Calculator Western
In Singapore, the BMI cut-off figures were revised in 2005, after studies have shown that Singaporeans including many Asian populations, have higher proportion of body fat and increased risk for cardiovascular diseases and diabetes mellitus as compared with general BMI recommendations in other countries.
Rather than an emphasis on weight, the BMI cut-offs are presented with an emphasis on health risk in the table below.
|BMI (kg/m2) for adults||Health risk|
|27.5 and above||High Risk: Your weight is further above healthy range. It increases the risk for developing many chronic diseases such as heart disease and type 2 diabetes, and decreases overall quality of life. Talk to your healthcare provider about your ideal body weight and how to make healthy lifestyle changes.|
|23 – 27.4||Moderate Risk: Your risk for developing type 2 diabetes and other chronic diseases are higher. Talk to your healthcare provider about your ideal body weight and how to make healthy lifestyle changes.|
|18.5 – 22.9||Low risk: Continue exercising and eating healthfully.|
|Below 18.5||Risk of nutritional deficiency diseases and osteoporosis.|
*BMI may not apply to athletes who tend to have large muscle mass, elderly people, pregnant women and children.
Optimal Waist Circumference for Asians
Sometimes even when your BMI is within healthy range, having too much fat around the abdomen (apple-shaped body) will still put you at risk for heart disease and diabetes. Below are the target goals for waist circumference measurements.
|Equals or less than 90cm (35.5 in)||Equals or less than 80cm (31.5 in)|
How accurate is BMI?
Scientists have said that BMI cannot distinguish between fat and muscle. Muscle tends to be heavier and can move more toned individuals into the overweight status, even if their fat levels are low.
BMI also doesn’t tease apart different types of fat, each of which can have different metabolic effects on health. For instance, Visceral fat is a type of body fat that’s stored within the abdominal cavity also known as Belly fat. It’s located near several vital organs, including the liver, stomach, and intestines.
Visceral fat is more harmful that fat that is stored just under the skin. Thin people can have high levels of visceral fat, even though they might be considered healthy by BMI standards, but they may pose a higher risk of developing health problems related to weight gain.
Currently without a viable way to change how we measure body fat, BMI is still the best option.
More About BMI calculator
What is the normal BMI?
An ideal BMI for most adults is in the 18.5 to 24.9 range. For young people and children aged 2 to 18, the BMI calculation takes into account age and gender as well as height and weight. You are in the underweight range is your BMI is below 18.5 and overweight if your BMI is over 25.
How do I calculate my BMI?
Using the Body Mass Index calculator to calculate using a person’s height and weight. The formula is BMI = kg/m2 where kg is a person’s weight in kilograms and m2 is their height in metres squared.
How do you calculate BMI with height and weight?
First you must know your weight and your height to determine your Body Mass Index (BMI). The formula is BMI = kg/m2 where kg is a person’s weight in kilograms and m2 is their height in metres squared.
How do you calculate BMI in kg?
You can calculate your BMI manually using the metric system Formula: weight (kg) / (height (m))2 Calculation: (weight (kg) / height (cm) / height (cm)) x 10,000.