Enter your weight in kg or lbs and get your BMI, ideal weight, daily calories, macros, water intake and personalised plan — instantly, free, no sign-up.
Medical DisclaimerThis BMI Calculator is for general informational purposes only and does not provide medical advice. Results are estimates and should not be used as a substitute for professional medical consultation or diagnosis. Always consult a qualified healthcare professional before making changes to your diet or exercise routine.
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BMI Calculator for Women & Men — Australia
Our free BMI calculator supports women and men across Australia and worldwide. Enter your weight in kilograms (kg) or pounds (lbs), height in centimetres or inches, age, sex, and activity level — and get a complete health picture in seconds. No sign-up, no ads on your results, 100% private.
BMI calculator for women
Female-specific BMR formula gives accurate calorie targets. Healthy BMI for women: 18.5–24.9.
BMI calculator kg
Full metric support — weight in kg, height in cm. Switch to imperial (lbs/in) anytime.
Weight calculator
Find your ideal weight range, how far you are from it, and a weekly timeline to get there.
BMI calculator Australia
Uses WHO and Australian Department of Health BMI standards. Free, private, no data stored.
What does your BMI number mean?
A BMI below 18.5 means underweight. Between 18.5–24.9 is healthy. Between 25–29.9 is overweight. A BMI of 30 or above is classified as obese. This calculator gives you far more than just a number — it shows you exactly what to eat, how many calories you need, and a personalised action plan based on which tier you fall into.
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Frequently Asked Questions
What is BMI?
Body Mass Index (BMI) is a numerical measure calculated from a person's weight and height. It is the most widely used screening tool to assess whether an adult is in a healthy weight range. BMI is used by the World Health Organization (WHO), the Australian Department of Health, the NHS, the CDC, and health authorities worldwide.
BMI was developed in the 19th century by Belgian mathematician Adolphe Quetelet. Despite being over 150 years old, it remains one of the most practical population-level indicators of weight-related health risk.
Example: a woman weighing 65 kg standing 1.65 m tall has a BMI of 65 ÷ (1.65 × 1.65) = 23.9 — comfortably in the healthy range.
BMI categories — women and men
Category
BMI Range
Health risk
Underweight
Below 18.5
Nutritional deficiency, hormone disruption
Normal weight
18.5–24.9
Lowest health risk
Overweight
25–29.9
Moderate risk — type 2 diabetes, heart disease
Obese class I
30–34.9
High risk
Obese class II–III
35+
Very high risk
Healthy BMI for women
A healthy BMI for women is 18.5 to 24.9. Women naturally carry more body fat than men at the same BMI — this is physiologically normal and healthy. Women with a BMI below 18.5 may experience hormonal disruption, bone density loss, and fertility issues. Women with a BMI above 25 face increased risk of type 2 diabetes, cardiovascular disease, sleep apnoea, and certain cancers.
Healthy BMI for men
A healthy BMI for men is also 18.5 to 24.9. Men typically carry more muscle mass, which can push BMI higher without excess body fat — this is particularly relevant for athletes. This calculator uses sex-specific BMR formulas to give more accurate calorie targets for both women and men.
What is BMR?
Basal Metabolic Rate (BMR) is the calories your body burns at complete rest — just to keep your heart beating, lungs breathing, and temperature regulated. This calculator uses the Mifflin-St Jeor equation, the most clinically accurate BMR formula for general use.
What is TDEE?
Total Daily Energy Expenditure (TDEE) is your BMR multiplied by your activity level. It is the total calories you burn per day including all movement and exercise. Eating at TDEE = maintain weight. Below TDEE = lose weight. Above TDEE = gain weight/muscle.
Limitations of BMI
BMI does not directly measure body fat. It cannot distinguish between muscle and fat mass, which means muscular individuals (athletes, bodybuilders) may be classified as overweight despite having low body fat. It also does not account for age, sex-based fat distribution differences, ethnicity, or bone density. Use BMI as one of several health indicators — not as a standalone diagnosis.
Health & BMI Blog
Evidence-based articles about BMI, weight management, nutrition, and healthy living for Australians.
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Women's Health
What is a healthy BMI for women in Australia?
Everything Australian women need to know about BMI, healthy weight ranges, and what the numbers actually mean for your health.
June 2025 · 8 min read
Nutrition
How to calculate BMI in kg — a complete guide
Step-by-step guide to calculating your Body Mass Index using kilograms and centimetres, with worked examples and interpretation tips.
June 2025 · 6 min read
Weight Loss
BMI vs body fat percentage — which matters more?
BMI and body fat percentage measure different things. Understanding both helps you get a far more accurate picture of your health.
June 2025 · 7 min read
Calories
How many calories should I eat per day? (Australia)
Your daily calorie needs depend on your weight, height, age, sex and activity level. Here is how to calculate yours accurately.
June 2025 · 7 min read
Exercise
The best exercises to lower BMI — ranked by effectiveness
Not all exercise burns fat equally. We rank the most effective workouts for lowering your BMI based on calorie burn and sustainability.
June 2025 · 9 min read
Frequently Asked Questions
Everything you need to know about BMI, weight, calories, and how this calculator works.
About My BMI Cal
My BMI Cal is a free, comprehensive online BMI calculator built for women and men in Australia and worldwide. Our mission is to give everyone access to accurate, personalised health metrics — with no ads cluttering your results, no sign-up required, and no data ever stored or shared.
Every calculation runs entirely in your browser using clinically validated formulas. Your data never leaves your device.
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Instant results
No loading screens. Get your BMI, calories, macros, and health plan the moment you click Calculate.
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Optimised for women
Female-specific BMR formula (Mifflin-St Jeor) gives accurate calorie targets for women of all ages.
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Metric & imperial
Full support for kg/cm and lbs/inches. Switch with one tap, results update instantly.
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100% private
All calculations run client-side in JavaScript. Nothing is ever sent to a server or stored.
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Goal-specific plans
5 distinct goal modes — each with unique calorie targets, macros, tips, and food recommendations.
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Built for Australia
Uses WHO and Australian Department of Health BMI classifications. Free for all Australians.
Formulas & methodology
BMI: Standard WHO formula — weight (kg) ÷ height² (m²). BMR: Mifflin-St Jeor equation — most accurate general-purpose BMR formula per clinical research. TDEE: BMR × Harris-Benedict activity multiplier. Ideal weight range: BMI 18.5–24.9 applied to your height. Water intake: 35 ml per kg body weight per day. Macros: Standard sports nutrition ratios adjusted per goal and BMI tier.
Medical disclaimer
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Medical DisclaimerThis BMI Calculator is for general informational purposes only and does not provide medical advice. Results are estimates and should not be used as a substitute for professional medical consultation or diagnosis. Always consult a qualified healthcare professional before making changes to your diet or exercise routine.
Contact Us
Have a question, suggestion, or found an issue? We'd love to hear from you. Fill out the form below and we'll get back to you within 1–2 business days.
You can also reach us directly at: hello@mybmical.com.au
✅ Thank you! Your message has been sent. We'll be in touch within 1–2 business days.
Privacy Policy
Last updated: 1 June 2025
My BMI Cal ("we", "us", "our") operates the website mybmical.com.au. This Privacy Policy explains how we handle information when you use our website.
1. Information we collect
Calculator data: All BMI calculations — including your weight, height, age, sex and activity level — are processed entirely within your browser using JavaScript. This data is never transmitted to our servers, never stored, and never shared with third parties. We have no access to any values you enter into the calculator.
Usage data: We may collect anonymised, non-personal usage statistics (such as page views, browser type, and general geographic region) through analytics tools to help us improve the website. This data cannot be used to identify you personally.
Contact form: If you contact us via our contact form, we collect your name, email address, and the content of your message solely for the purpose of responding to your enquiry. We do not add you to any mailing list without your explicit consent.
2. Cookies
Our website may use essential cookies required for basic website functionality. We may also use third-party advertising cookies (such as Google AdSense) which may collect anonymised data to serve relevant advertisements. You can disable cookies in your browser settings at any time.
3. Google AdSense
We use Google AdSense to display advertisements on this website. Google AdSense uses cookies to serve ads based on a user's prior visits to our website or other websites. Google's use of advertising cookies enables it and its partners to serve ads based on your visit to our site. You may opt out of personalised advertising by visiting Google Ads Settings. For more information, please see Google's Privacy Policy.
4. Third-party links
Our website may contain links to third-party websites. We are not responsible for the privacy practices of those websites and encourage you to review their privacy policies.
5. Children's privacy
Our website is not directed at children under the age of 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us and we will delete it promptly.
6. Your rights (Australian Privacy Act)
Under the Australian Privacy Act 1988, you have the right to access personal information we hold about you, request corrections, and lodge a complaint with the Office of the Australian Information Commissioner (OAIC) if you believe your privacy has been breached.
7. Changes to this policy
We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated date. Continued use of the website after changes constitutes acceptance of the updated policy.
8. Contact us
For privacy-related enquiries, contact us at: privacy@mybmical.com.au
Terms of Service
Last updated: 1 June 2025
By using mybmical.com.au, you agree to these Terms of Service. Please read them carefully.
1. Use of the calculator
The BMI calculator provided on this website is for general informational and educational purposes only. Results are mathematical estimates based on the information you provide and widely accepted health formulas. They do not constitute medical advice, diagnosis, or treatment recommendations.
2. Medical disclaimer
Always consult a qualified healthcare professional — such as your GP, a registered dietitian, or an accredited exercise physiologist — before making any changes to your diet, exercise routine, or health practices based on information from this website.
3. Accuracy
We strive to provide accurate calculations using clinically validated formulas. However, we make no guarantees regarding the accuracy, completeness, or suitability of results for any individual's specific health circumstances.
4. Intellectual property
All content on this website — including text, design, graphics, and code — is the intellectual property of My BMI Cal and may not be reproduced without written permission.
5. Governing law
These terms are governed by the laws of Australia. Any disputes shall be subject to the exclusive jurisdiction of Australian courts.
6. Contact
For terms-related enquiries: legal@mybmical.com.au