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BMI Calculator
BMI uses your height and weight to estimate whether you’re in a healthy range. Enter your details and get instant guidance.
What your BMI is really telling you
A single number that compares your weight to your height. Useful as a starting point, and easy to over-read.
Because it needs only two measurements, BMI has been used for decades in clinics and public-health research. It is also one of the first numbers our care team looks at when deciding whether a medically supervised weight-management programme is appropriate.
What BMI cannot do is look inside your body. It does not know whether a pound is muscle or fat, or where that weight sits.
And those things matter a great deal. That is why BMI belongs alongside your waist measurement, your bloodwork and your history. It is informative in context and misleading on its own.
Where the numbers sit
The categories below are those used by the World Health Organization and the CDC for adults aged 20 and over.
Four things BMI does not know
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Muscle weighs the same as fat
BMI cannot tell them apart. A trained athlete carrying a lot of lean mass can land in the overweight range while being metabolically healthy by every other measure.
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Where the weight sits matters
Fat around the abdomen carries more risk than fat on the hips and thighs. BMI treats both identically, which is why waist circumference is usually measured alongside it.
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Thresholds shift with ancestry
People of South and East Asian descent tend to develop weight-related conditions at lower BMIs, so several guidelines apply lower cut-offs for these populations.
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Age and life stage change it
Body composition shifts as we age, and BMI is not designed for children, pregnancy or breastfeeding. Children are assessed on growth percentiles instead.
BMI and weight-loss treatment
BMI is one of the criteria our care team weighs when considering prescription options, including GLP-1 medications. Guidelines generally point to:
Meeting a number does not make treatment appropriate, and missing one does not rule it out. Momentum Health 360 reviews your full history, current medications and goals before anything is prescribed. BMI is where that conversation starts, not where it ends.
Contact Momentum Health 360Moving toward a healthier BMI
A steady one to two pounds a week is the rate most clinicians consider both safe and sustainable. Faster loss tends to cost muscle along with fat, and muscle is the thing you least want to give up.
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Keep the deficit modest
Roughly 500 calories a day below maintenance produces about a pound a week. Deeper cuts rarely hold, and rebound is common.
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Eat enough protein
Protein protects lean mass while you are in a deficit and keeps you fuller between meals, which is exactly when most people under-eat it.
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Train, do not just diet
Resistance work signals your body to keep the muscle it has. Combined with adequate protein, it changes what you lose, not only how much.
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Protect sleep and stress
Short sleep and sustained stress both push appetite up and make adherence harder. They are not side issues.
BMI, answered
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered the healthy range. It is the band associated with the lowest risk of weight-related conditions across large populations. It is a range rather than a target, and it can read differently depending on your build, your ancestry and your medical history.
Is BMI accurate?
It is accurate at what it measures: the ratio of your weight to your height. It is not a measure of body fat, fitness or health. For most people it gives a reasonable signal; for very muscular people, older adults and some ethnic groups it can read misleadingly high or low. Treat it as one input among several.
Does BMI differ for men and women?
The formula and the adult categories are identical. Body composition does differ, since women typically carry a higher percentage of body fat at the same BMI, but the thresholds themselves are not sex-specific.
What BMI do you need for weight-loss medication?
Guidelines generally point to a BMI of 30 or above, or 27 or above alongside a weight-related condition such as type 2 diabetes, high blood pressure or sleep apnea. This is a guideline, not a gate. Contact Momentum Health 360 and we will review your full health history before deciding whether any treatment is appropriate for you.
Why does my BMI say overweight when I am fit?
Because BMI counts muscle as weight. If you train regularly and carry above-average lean mass, your BMI can sit in the overweight band while your body fat and metabolic markers are healthy. Waist circumference and a body-composition assessment will tell you far more in that situation.
How quickly can I lower my BMI?
At a sustainable one to two pounds per week, most people see a BMI point come off every few weeks, depending on their height and starting weight. The pace that lasts almost always beats the pace that is fastest.
Does BMI work for children?
Not in the form shown here. Children and teenagers are assessed using age- and sex-specific growth percentiles, because healthy body composition changes throughout development. This calculator is intended for adults aged 20 and over.
Other tools that help
BMI tells you where you are. These help you work out what to do next.
Medical disclaimer. This calculator and the information on this page are for general educational purposes and are not medical advice, diagnosis or treatment. BMI is a screening measure and does not account for muscle mass, bone density, fat distribution or overall body composition, and it may read differently across ethnic groups, ages and life stages. It does not determine eligibility for any medication or programme. Contact Momentum Health 360 about your individual health before changing how you eat, train or take medication.
One last step
Where should we send your result?
Enter your details to see your personalized BMI result.
We’ll never share your information.
Body Mass Index
Body Mass Index (BMI) is a measurement tool that uses your height and weight to estimate if your weight is in a healthy range for your height.
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Underweight (< 18.5)
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Healthy Weight (18.5 – 24.9)
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Overweight (25 – 29.9)
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Obesity (30+)
BMI may not be accurate for all ethnic groups and does not account for muscle mass, bone density, or overall body composition. It is a screening tool, not a diagnosis. Contact Momentum Health 360 for personalized guidance.