Your details
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—
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BMI scale
Underweight
<18.5Normal
18.5–24.9Overweight
25–29.9Obese
30+
<18.5Normal
18.5–24.9Overweight
25–29.9Obese
30+
Your BMI
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body mass index
Healthy weight range
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for your height
Weight to healthy
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adjustment needed
Ideal weight
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mid healthy range
Healthy weight tips
BMI has limitations
BMI doesn't distinguish between muscle and fat, and doesn't account for where fat is distributed. Athletes may have a high BMI despite being very healthy. Always consider BMI alongside other health measures like waist circumference.
Small changes matter
Even a 5-10% reduction in body weight can significantly reduce health risks. You don't need to reach an ideal BMI to benefit — any movement toward a healthy range improves health outcomes.
Waist circumference matters
For Australians, health risk increases when waist circumference exceeds 94cm for men or 80cm for women. Central obesity (belly fat) is a stronger predictor of metabolic risk than BMI alone.
Talk to your GP
BMI is a screening tool, not a diagnosis. If you are concerned about your weight or health, speak with your GP who can assess your overall health picture and recommend personalised strategies.
Sustainable habits win
Crash diets rarely work long-term. Research consistently shows that small, sustainable changes to diet and activity levels produce the best long-term outcomes. Aim for gradual, steady progress.
Mental health matters too
A healthy relationship with food and your body is just as important as physical health. If you are struggling with body image or disordered eating, please reach out to a healthcare professional or the Butterfly Foundation.
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Frequently asked questions
What is a healthy BMI for Australians?
For most Australian adults, a healthy BMI is between 18.5 and 24.9. A BMI below 18.5 is considered underweight, 25-29.9 is overweight, and 30 or above is obese. For older Australians (65+), a slightly higher BMI of 22-27 may be associated with better health outcomes.
How do I calculate BMI?
BMI is calculated by dividing your weight in kilograms by your height in metres squared: BMI = kg ÷ m². For example, a person weighing 75kg and 1.75m tall has a BMI of 75 ÷ (1.75 × 1.75) = 24.5, which is in the healthy range.
Is BMI accurate for everyone?
BMI has limitations. It can overestimate health risk for very muscular people and underestimate it for those with low muscle mass. It also does not account for age, sex, or body fat distribution. For people of Asian background, health risks may begin at a lower BMI threshold (around 23).
What should I do if my BMI is outside the healthy range?
Speak with your GP who can assess your overall health and provide personalised advice. Small, sustainable lifestyle changes — including a balanced diet and regular physical activity — are the most effective long-term strategies. Australia's physical activity guidelines recommend at least 150-300 minutes of moderate activity per week.