Check if you qualify
Free tool
Work out your BMI in seconds, see which band it falls in, and understand what the number can and cannot tell you about your health.
The calculator
Enter your height and weight and the number appears straight away. It runs entirely in your browser, so nothing you type here is saved or sent to us.
Two numbers, no sign up, no email address
Nothing you type here is saved or sent to us.
This calculator is general information, not a diagnosis and not medical advice. A doctor registered with the HPCSA looks at far more than one number before deciding anything.
The honest part
BMI is a quick screening number that can point you toward a conversation about your health. It was never designed to describe any single person on its own.
A first line, not a conclusion
If your BMI sits above the healthy range, that is a reason to talk to a doctor. It is not a diagnosis in itself. Think of it as the opening line of a conversation about your health rather than the answer.
Build and body composition are invisible to it
BMI only knows total weight. A rugby forward or a regular gym-goer carries dense muscle, so they can land in the overweight band on paper while being genuinely fit. The reverse happens too: someone with little muscle can sit in the healthy range and still carry risk the number hides.
Waist size adds what BMI misses
Fat around the middle carries more health risk than fat on the hips and thighs, and BMI treats both the same. That is one reason a doctor may also measure your waist.
Age, body type and ancestry all shift the picture
BMI was built mainly from older studies of European populations, so it reads differently across ages, body types and ethnic groups. Older adults lose muscle naturally. For some groups, risk rises at a lower BMI than the standard bands suggest.
The bands
These are the standard bands used around the world and here in South Africa. They are guides, not verdicts.
| BMI | Band | What it usually means |
|---|---|---|
| Under 18.5 | Under the healthy range | Below the range considered healthy for your height. Weight loss is not the goal here, and weight that came off on its own is worth raising with a doctor. |
| 18.5 to 24.9 | Healthy range | The range most guidelines describe as healthy. Health still depends on far more than this one figure. |
| 25 to 29.9 | Overweight | Above the healthy range. From a BMI of 27, treatment can be considered when a weight-related condition sits alongside it. |
| 30 to 34.9 | Obesity | The range where doctors generally start to consider GLP-1 treatment on the basis of BMI alone. |
| 35 to 39.9 | Obesity, class 2 | Weight-related health risks are higher in this band, and a proper medical assessment matters more, not less. |
| 40 and above | Obesity, class 3 | The highest band. A doctor will want to look at your full health picture and at every option open to you. |
You take your weight in kilograms and divide it by your height in metres, squared. Say you weigh 90 kg and you are 1.70 m tall. First multiply your height by itself: 1.70 x 1.70 = 2.89. Then divide: 90 divided by 2.89 gives a BMI of about 31. The calculator above does exactly that.
Two people with the same BMI can have very different health, which is exactly why the number needs context. Read the fuller guide to what BMI really means.
BMI does play a defined role when doctors consider whether GLP-1 medication may suit someone. As a general guide, treatment is usually considered at a BMI of 30 or above, or from a BMI of 27 when there is a weight-related condition such as type 2 diabetes, high blood pressure, high cholesterol, sleep apnoea or fatty liver.
This class of treatment is not suitable for everyone. It is not used in pregnancy or while breastfeeding, or by anyone with a personal or family history of medullary thyroid cancer or MEN 2. Results also differ from person to person, and the eligibility line is a starting point rather than the whole assessment. See who this is not right for.
This is general information and not medical advice. A registered doctor reviews your full health picture and decides what, if anything, suits you as an individual.
The eligibility check is free and takes about two minutes. You only pay if a doctor recommends treatment for you.
Before you decide
Straight answers. If yours is not here, the FAQ goes further, or you can ask us directly.
Not on its own. A BMI of 30 or above puts you in the range where GLP-1 treatment is normally considered, which is the starting point rather than the decision. A doctor registered with the HPCSA still reviews your medical history, the other medicines you take and any conditions you live with before recommending anything.
The arithmetic is exact: it is the same formula a clinic uses. What it cannot do is judge your build, your muscle, where your weight sits or how fit you are. Measure your height without shoes and weigh yourself at a consistent time of day, and the number will be as good as BMI ever gets.
Nothing. The calculator and the eligibility check are both free, with no obligation. If you go ahead, a once-off consultation is R850 and the full programme starts from R299 a month, with an annual option at R2,999. You only pay for treatment if a doctor recommends it for you. The detail is on our pricing page.
We will not promise you a number. In clinical trials, average weight loss ran from roughly 8% to over 20% of body weight depending on the medication and dose, and your result can be different. What we can commit to is a proper assessment, genuine SAHPRA-registered medication dispensed by a licensed South African pharmacy, and a doctor who reviews you as you go.
Then you are told so, plainly, and pointed toward other options. A no is a real answer here. You pay nothing for medication that is not recommended for you.
No. This calculator runs in your browser and the numbers never leave your device. Nothing on this page is stored or sent to us. When you go on to the full assessment, your medical information is handled under POPIA and used only to provide your care.
Answer a few questions and see whether GLP-1 treatment could suit you. Free, no obligation, and you only pay if a doctor recommends treatment for you.
Check if you qualify Free, takes about 2 minutes, no obligation.