BMI Calculator for Weight Loss Surgery
Check whether your body mass index makes you a candidate for weight loss surgery, and get a price estimate in a few simple steps.
Find Out If You Qualify for Weight Loss Surgery
Calculating your body mass index (BMI) is the first step in working out whether weight loss surgery may be an option for you. Our calculator works out your BMI, checks it against current eligibility guidelines, and gives you a price estimate for treatment, all in a few simple steps.
Check Your Eligibility
Answer a few quick questions to see if you may be eligible for bariatric surgery
What is your height and weight?
What is BMI and how is it calculated?
Body mass index (BMI) is a measure of your weight relative to your height. It is calculated by dividing your weight in kilograms by your height in metres squared. For example, a person who is 170cm tall and weighs 110kg has a BMI of 38.
BMI is not a perfect measure. It does not distinguish between muscle and fat, and it does not tell us where fat is carried on the body. However, it remains the standard starting point used by surgeons, health funds and Medicare to assess eligibility for weight loss surgery.
BMI categories
| Category | Standard BMI range | BMI range for people of Asian descent |
|---|---|---|
| Underweight | Below 18.5 | Below 18.5 |
| Healthy weight | 18.5 to 24.9 | 18.5 to 22.9 |
| Overweight | 25 to 29.9 | 23 to 27.4 |
| Obesity Class I | 30 to 34.9 | 27.5 to 32.4 |
| Obesity Class II | 35 to 39.9 | 32.5 to 37.4 |
| Obesity Class III | 40 and above | 37.5 and above |
Lower BMI ranges apply for people of Asian descent because the health risks associated with excess weight, particularly type 2 diabetes and heart disease, occur at lower BMI levels. Our calculator takes this into account automatically.
What BMI do I need for weight loss surgery?
Under current guidelines, weight loss surgery is generally considered when:
- Your BMI is 35 or above, or
- Your BMI is 30 or above and you have a weight related health condition such as type 2 diabetes, sleep apnoea, high cholesterol, gout or liver disease.
- For people of Asian descent, the equivalent thresholds are a BMI of 32.5 or above, or 27.5 or above with a weight related health condition.
BMI is only the starting point. Your overall health, your weight history, previous weight loss attempts and your readiness to make long term lifestyle changes are all part of the assessment. Every patient is assessed individually by our surgeons and multidisciplinary team, and the final decision on whether surgery is right for you is made together at your consultation.
What if my BMI is below the surgical range?
If your BMI is below the thresholds above, surgery may not be indicated at this stage, but that does not mean we cannot help. We offer the Allurion balloon, the intragastric balloon and a comprehensive non-surgical program including dietitian support, psychological counselling and medical management. These options can be discussed with our team at any BMI level.
What happens after you check your eligibility?
Get your result and estimate.
The calculator shows your BMI, whether you may be eligible for surgery, and a cost guide based on whether you hold private health insurance.
Book a consultation.
Your journey starts with an initial consultation with one of our experienced surgeons. We recommend a GP referral, and we can help you arrange one.
Comprehensive assessment.
Before any surgery you will be assessed by our Specialist Physician, bariatric dietitian and psychologist to make sure the plan is safe and right for you.