Use these body mass index (BMI) calculators to give yourself an indication of whether your weight may be affecting your health. These calculators are provided courtesy of The Calculator Site. There are two calculation options available - metric and imperial.
1) Metric BMI Calculator
2) Imperial BMI Calculator
Use the charts below to locate your height and weight. The shaded areas correspond to BMI values that are healthy, overweight, obese and extremely obese. Be mindful that the figures are only a guide, and that it is not a tool to determine your ideal body weight, it is a tool to help to show if your weight is increasing your risk for disease.7
The following charts are adapted from The University of Vermont Adult body mass index (BMI) chart.
Body mass index chart - weight from 95-245 pounds
Adult BMI chart showing ranges "under healthy weight: BMI <18.5," "healthy weight: BMI 18.5-24" and "overweight: BMI 25-29.9."
Body mass index chart - weight from 250-400 pounds
Adult BMI chart showing ranges "obese I: BMI 30-34.9," "obese II: BMI 35-39.9" and "obese III: BMI ≥ 40."
The standard weight status categories associated with BMI ranges for adults are shown in the following table:
|30.0 and above||Obese|
A BMI of less than 18.5 indicates that you are underweight, so you may need to put on some weight. You are recommended to ask your doctor or a dietitian for advice.
A BMI of 18.5-24.9 indicates that you are at a healthy weight for your height. By maintaining a healthy weight, you lower your risk of developing serious health problems.
A BMI of 25-29.9 indicates that you are slightly overweight. You may be advised to lose some weight for health reasons. You are recommended to talk to your doctor or a dietitian for advice.
A BMI of over 30 indicates that you are heavily overweight. Your health may be at risk if you do not lose weight. You are recommended to talk to your doctor or a dietitian for advice.
According to the World Health Organization (WHO), there has been growing debate about whether there are possible needs for developing different BMI cut-off points for different ethnic groups. This is due to the increasing evidence that the associations between BMI, percentage of body fat, and body fat distribution differ across populations and therefore, the health risks increase below the cut-off point of 25 kg/m2 that defines overweight in the current WHO classification.
The WHO Expert Consultation have concluded that the proportion of Asian people with a high risk of type 2 diabetes and cardiovascular disease is substantial at BMIs lower than the existing WHO cut-off point for overweight (= 25 kg/m2).
However, the cut-off point for observed risk varies from 22 kg/m2 to 25 kg/m2 in different Asian populations and for high risk, it varies from 26 kg/m2 to 31 kg/m2. The Consultation, therefore, recommend that the current WHO BMI cut-off points in the table below should be retained as the international classification.
The cut-off points of 23, 27.5, 32.5 and 37.5 kg/m2 are to be added as points for public health action. It was, therefore, recommended that countries should use all categories (i.e., 18.5, 23, 25, 27.5, 30, 32.5 kg/m2, and in many populations, 35, 37.5, and 40 kg/m2) for reporting purposes, with a view to facilitating international comparisons.
The WHO international classification of adult underweight, overweight and obesity according to BMI
principal cut-off points
additional cut-off points
|Obese class I||30.00-34.99||30.00-32.49
|Obese class II||35.00-39.99||35.00-37.49
|Obese class III||≥40.00||≥40.00|
For clinical and research purposes, obesity is divided into three categories: Class I (30-34.9), Class II (35-39.9) and Class III (40+). With the growth of extreme obesity, researchers and clinicians have further divided Class III into super-obesity (BMI 50-59) and super-super-obesity (BMI 60+).
Studies have shown that people with a BMI of 30 or more have an increased risk of death from diseases such as heart disease, diabetes and colorectal cancer.8 According to some estimates, a BMI of 30 and over also increases the risk of death from any cause by 50-150%.11
There are also significant issues with being underweight on the BMI scale such as an increased risk of malnutrition, osteoporosis and anemia.
Ethnicity, BMI and diabetes risk
Certain ethnic groups including black or Asian, are at risk of certain health problems at a lower BMI than others.
South Asian and Chinese adults, who have a higher risk of developing type 2 diabetes than white populations, are advised to maintain a BMI lower than the standard 25.13
The advice is:
- BMI of 23: Asians with a BMI score of 23 or more are at increased risk of developing type 2 diabetes
- BMI of 27.5: Asians with a BMI of 27.5 or more are at high risk of developing type 2 diabetes.
Although the evidence is less clear-cut, black people and other minority groups are also advised to maintain a BMI below 25 to reduce their risk of type 2 diabetes.
Speak to your doctor for more information.
On the next page we look at how BMI is calculated for children and teens, the health consequences of overweight and obese adults and the limitations of BMI.