A BMI calculator allows you to work out your Body Mass Index (BMI). BMI is a method used to estimate your body fat based on your height and weight. Here we explain how the BMI calculator works, how you can work out your own BMI and discover whether weight loss surgery is something you could consider.
How to use the BMI calculator
Working out your BMI is a good way to find out if you are obese and should consider loosing weight. In extreme cases (only if you have a BMI of more than 30), weight loss surgery may be an option. However, there are other factors that must be considered before we can determine a person’s actual state of health and what steps should be taken.
At the Obesity Clinic (Aleris Overvektsklinikk) we take account of your BMI as well as your waist and hip measurements. In addition, we assess your general health and look at any conditions you may have that are a direct consequence of obesity.
Work out your BMI using our BMI calculator
– and find out whether weight loss surgery may be appropriate for you.
Your BMI is:
Underweight (0 - 18.5)
Your BMI indicates that you are underweight. A healthy body weight is important for good health, many are not aware that underweight is unfortunate. For some, it can be difficult to gain weight. We recommend that you contact one of our skilled nutritional counselors for dietary guidance.
Normal Weight (18.5 - 25)
Your BMI indicates that you are of normal weight. Obesity surgery is not appropriate for you. Weight loss is also not recommended, but a healthy diet and regular physical activity are beneficial for maintaining good health.
Overweight (25 - 30)
Your BMI indicates that you are overweight. Your health may be at risk, but this is very individual. BMI can be misleading if you have high muscle mass. To assess your health risk, it is wise to use several goals. If you are a woman and your waist is greater than 88 cm, or if you are a man and your waist is over 100 cm then you have an increased risk of lifestyle diseases such as diabetes II, high blood pressure and cardiovascular disease. It is important that you do not increase your weight further, but try to reduce it slightly. If your BMI is higher than 27, the risk of obesity-related health problems is higher. Recent studies have shown that women with BMI 27.3 and men with BMI 27.8 have an increased incidence of high blood pressure, diabetes and heart disease.
Obesity (30 - 35)
Your BMI indicates that your overweight is a health hazard. If you have a BMI over 30 over time, you are at increased risk of getting diseases such as diabetes II, high blood pressure, cardiovascular disease, sleep-related disorders, and stress disorders. Waist above 88 cm for women and over 100 cm for men increase the risk. If your weight is established at this level and have tried several times to reduce your weight, surgery may be appropriate for you. Aleris offers treatment such as gastric bypass, gastric sleeve and sleeve bypass (SASI) surgery. Contact us today for non-binding and free dieting advice.
Serious obesity (35 - 40)
Your BMI indicates that you have severe obesity. If you have a BMI 35-39.9 over time, you have a significantly increased risk of getting diseases such as diabetes II, high blood pressure, cardiovascular disease, sleep-related disorders, involuntary childlessness and stress disorders. Overweight surgery may be appropriate for you. Aleris offers treatment such as gastric bypass, gastric sleeve and sleeve bypass (SASI) surgery. Surgery is a tool to change your lifestyle and gain a lasting, normal weight. Contact us today for non-binding and free dieting advice.
Very serious obesity (40 - -1)
Your BMI indicates that you have a very severe obesity. There is a great danger that you are, or are going to get sick because of your obesity. You have a significantly increased risk of diabetes II, high blood pressure, cardiovascular disease such as heart attack and stroke, sleep-related disorders, involuntary infertility and stress disorders. There are also many who have mental health problems related to their obesity. Aleris can offer treatment in the form of gastric bypass, sleeve bypass (SASI) or gastric sleeve. Surgery is a tool to change your lifestyle and gain a lasting, normal weight. Contact us today for non-binding and free dieting advice.
BMI is one of several measurements that give an indication of whether a person is underweight, overweight, or obese, or whether their weight is normal. BMI is one of several factors that can be used to assess whether someone might benefit from weight loss surgery. Other important factors include waist size and obesity-related illnesses such as diabetes 2, high blood pressure and high cholesterol levels.
Waist and hip measurements are also important
Both waist and hip size must also be measured. The ratio between waist and hip size gives an indication of how your body is made up and whether you are at risk of developing certain medical conditions. Belly fat has a huge impact on your health, since it affects both blood sugar and cholesterol levels. Fat on the thighs and buttocks is not as harmful.
BMI Table: These are the various categories
Set by the World Health Organisation (WHO)
Obesity, class 1
Obesity, class 2
Obesity, class 3
BMI is used to calculate weight loss after weight loss surgery
We use a BMI of 25 (normal weight) to calculate weight loss after weight loss surgery. In this way, we can compare someone who weighed 200 kg before their surgery with someone who weighed 95 kg. We work out what your weight would be if you had a BMI of 25 (normal weight). Then we calculate a percentage weight loss (in kg) over this BMI 25 baseline.
Do you have any questions about weight loss surgery?
If you have any other questions about weight loss surgery, contact Aleris Obesity Clinic.
From 2005 Aleris Obesity Clinic has performed approx. 8,000 weight loss surgeries. We have therefore performed more weight loss procedures than any other medical facility in Norway. We also have the largest interdisciplinary bariatric medical team in the country. Read more about our weight loss patients’ personal stories here (in Norwegian)
Would you like to know more about weight loss surgery?
Book a free consultation with one of our bariatric surgeons. If you have any other questions about weight loss surgery contact the Obesity Clinic using the contact form below: