⚖️ BMI Calculator
Find your Body Mass Index in metric or imperial units — with a color-coded gauge, your healthy weight range, body-fat estimate, BMR and ideal weight. Free, instant & 100% private.
World Health Organization international cut-offs — used across Europe, the Americas, Africa and most of the world.
You're in the healthy range — nice work keeping it there.
🎯 Ideal Weight — Five Different Answers
There is no single "ideal weight." These classic clinical formulas each give a slightly different number for a 5'7" male. The healthy-BMI range is the widest — and the most modern.
Your current weight: 70 kg. Formulas are estimates and don't account for muscle, frame size or body composition.
📊 The BMI Categories — WHO (Standard), adults
⚕️ BMI is a quick screening number, not a diagnosis. It can over- or under-estimate body fat for athletes, older adults, pregnant women and children. For people under 20, age- and sex-specific BMI percentiles are used instead. Always consult a healthcare professional about your health.
More Than Just a BMI Number
A clear speedometer gauge plus the extra metrics that actually help you act on your result.
Metric & Imperial
Pick cm or ft·in for height and kg or lb for weight — independently. Numbers convert automatically with no re-typing.
Global & Asian Standards
Switch between the WHO international cut-offs and the WHO Asia-Pacific (Asian) standard used across India, China and Japan.
Visual BMI Gauge
A speedometer-style gauge with an animated needle shows exactly where you fall, not just a bare number.
Healthy Weight Range
See your personal healthy range and precisely how much to lose or gain to reach it.
Beyond Basic BMI
BMI Prime, Ponderal Index, estimated body-fat % and BMR give a fuller picture of your numbers.
Ideal Weight, 4 Ways
Compare Robinson, Miller, Devine and Hamwi formulas against the modern healthy-BMI range.
Private & Free
100% in your browser — nothing is uploaded. No login, no limits, dark mode and responsive to 280px.
How to Use the BMI Calculator
Four quick steps — no sign-up, results update as you type.
Choose units, sex & standard
Pick your height and weight units, your sex, and the WHO or Asian BMI standard for your region.
Enter height & weight
Drag the sliders or type your exact height, weight and age. Everything recalculates instantly.
Read your gauge
Find your BMI number, its category, and where the needle points on the color-coded gauge.
Plan your next step
Use your healthy range, BMR and the weight-to-lose/gain figure to set a realistic goal.
Frequently Asked Questions
What BMI is, the healthy range, accuracy and limits, men vs women, BMI Prime, BMR, and BMI for kids.
What is BMI (Body Mass Index)?
BMI is a simple number that compares your weight to your height. It's calculated as weight in kilograms divided by height in metres squared (kg/m²). It was designed as a quick way to screen whether an adult's weight sits in a range associated with good health — not as a precise measure of body fat.
How do I use this BMI calculator?
Pick metric or imperial units, choose male or female, then drag the height, weight and age sliders (or type exact values). Your BMI updates instantly, with an animated needle on the color-coded gauge, your healthy weight range, and how many kg or lb you'd need to lose or gain to reach it.
What is a healthy BMI range?
For most adults, the World Health Organization considers a BMI of 18.5 to 24.9 'normal weight'. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is classified as obese (in three classes). This tool shows your personal healthy weight range in kg or lb for your exact height.
Do BMI categories differ by country or ethnicity?
Yes. The WHO recommends lower thresholds for South and East Asian populations, who tend to face higher risk of type-2 diabetes and heart disease at a lower BMI. Under these WHO Asia-Pacific cut-offs — official in India, China, Japan and Singapore — overweight starts at 23 (not 25) and obesity at 25 (not 30). Use the 'BMI standard' toggle in the calculator to switch between the global WHO and Asian cut-offs.
Is BMI accurate for everyone?
No. BMI doesn't distinguish muscle from fat, so very muscular athletes can read as 'overweight' while having low body fat. It can also under-estimate fat in older adults who've lost muscle. It isn't valid for children, teens or pregnant women, and it doesn't capture where fat is stored — which matters for health.
Is BMI calculated differently for men and women?
The BMI formula itself is identical for men and women — same kg/m². However, at the same BMI women typically carry more body fat than men, which is why this calculator adjusts the body-fat estimate and ideal-weight figures by sex even though the BMI number doesn't change.
What is BMI Prime?
BMI Prime is your BMI divided by 25 (the upper limit of the healthy range). A value of 1.0 means you're exactly at the top of normal; below 1.0 is within the healthy range, above 1.0 shows how far over you are. It's a quick way to see your ratio to the healthy ceiling at a glance.
What is BMR and why is it shown?
BMR (Basal Metabolic Rate) is roughly how many calories your body burns at complete rest in a day, just to stay alive. We estimate it with the Mifflin-St Jeor equation using your height, weight, age and sex. It's a useful starting point for planning calorie intake to lose, maintain or gain weight.
How is BMI different for children and teens?
For anyone under 20, raw BMI isn't compared to fixed adult cut-offs. Instead, BMI is plotted against growth charts to find a percentile for the child's age and sex, because healthy body composition changes a lot during growth. Use a pediatric BMI-percentile tool for under-20s and treat the adult categories here as informational.