BMI Calculator for Women and Men: kg, Pounds or Stone
Find your body mass index, your healthy weight range for your height, and the weight that matches a target BMI. Select your country to set the units: metric, US pounds and feet, or UK stone. It runs in your browser, so nothing you enter is stored.
For information only. BMI is a screening number, not a diagnosis. Talk to a doctor about your health.
Your measurements
Your results
How to use the BMI calculator
- Pick your country. It sets the units: metric, US pounds and feet, or UK stone. You can change the units yourself too.
- Enter your height and weight. Age and sex are optional and do not change the adult result.
- Read your BMI, the category and your healthy weight range. The table shows where you sit.
- Switch to Weight for a target BMI to see what weight gives a BMI you choose at your height.
BMI formula and categories
BMI = weight in kg ÷ (height in metres)². In pounds and inches it is 703 × weight ÷ height². For 70 kg at 1.70 m: 70 ÷ 2.89 = 24.2.
The World Health Organization uses these adult categories for women and men:
| BMI | Category |
|---|---|
| Under 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight |
| 25 to 29.9 | Overweight |
| 30 and over | Obese |
Healthy weight for your height
A BMI between 18.5 and 24.9 is the healthy range for adults. Here is that range for some common heights:
| Height | Healthy weight (kg) | Healthy weight (lb) |
|---|---|---|
| 150 cm | 41.6 to 56.0 kg | 92 to 124 lb |
| 160 cm | 47.4 to 63.7 kg | 104 to 141 lb |
| 170 cm | 53.5 to 72.0 kg | 118 to 159 lb |
| 180 cm | 59.9 to 80.7 kg | 132 to 178 lb |
| 190 cm | 66.8 to 89.9 kg | 147 to 198 lb |
BMI chart for adults
Weight in kg for each height at the main BMI cut-offs. The same chart applies to women and men.
| Height | Underweight | Healthy | Overweight | Obese |
|---|---|---|---|---|
| 150 cm | under 41.6 | 41.6 to 56.0 | 56.3 to 67.3 | 67.5+ |
| 155 cm | under 44.4 | 44.4 to 59.8 | 60.1 to 71.8 | 72.1+ |
| 160 cm | under 47.4 | 47.4 to 63.7 | 64.0 to 76.5 | 76.8+ |
| 165 cm | under 50.4 | 50.4 to 67.8 | 68.1 to 81.4 | 81.7+ |
| 170 cm | under 53.5 | 53.5 to 72.0 | 72.3 to 86.4 | 86.7+ |
| 175 cm | under 56.7 | 56.7 to 76.3 | 76.6 to 91.6 | 91.9+ |
| 180 cm | under 59.9 | 59.9 to 80.7 | 81.0 to 96.9 | 97.2+ |
| 185 cm | under 63.3 | 63.3 to 85.2 | 85.6 to 102.3 | 102.7+ |
| 190 cm | under 66.8 | 66.8 to 89.9 | 90.3 to 107.9 | 108.3+ |
| 195 cm | under 70.3 | 70.3 to 94.7 | 95.1 to 113.7 | 114.1+ |
BMI and health
A higher BMI is linked with a higher risk of type 2 diabetes, heart disease, high blood pressure and some cancers. A very low BMI is linked with low energy, weak bones and a weaker immune system. These are averages across large groups. Your own risk also depends on your waist size, fitness, diet, family history and age, so BMI is a prompt to look further, not a verdict.
BMI for women and for men
The BMI formula and the adult categories are the same for women and men. The difference is in body composition: at the same BMI, women on average carry more body fat than men. So a BMI number can mean a slightly different amount of fat for each person.
That is why BMI is best used as a first check, together with waist size, activity and advice from a doctor.
BMI for children and teens
For children and teens aged 2 to 19, BMI is not compared with the adult ranges. It is read as a percentile for the child’s age and sex using growth charts, such as those from the CDC or WHO. This calculator shows the BMI number only, so use a growth chart or ask a doctor to read it for a child.
What BMI does not tell you
- It does not separate muscle from fat, so very muscular people can show a high BMI.
- It does not show where fat is stored. Waist size is a useful second check.
- Older adults may lose muscle and height, which can hide changes.
- Risk can start at lower BMI values for some groups. For many people of Asian descent, the WHO notes that health risk can rise from a BMI of about 23.
If your BMI is outside the healthy range, or you are worried about your weight, a doctor or dietitian can give advice that fits you.
Frequently asked questions
What is BMI?
BMI, or body mass index, is your weight in kilograms divided by your height in metres squared. It is a quick screening number for whether weight is low, healthy or high for your height.
How do I calculate BMI?
Divide your weight in kg by your height in metres squared. In pounds and inches, multiply weight by 703 and divide by height in inches squared. This calculator does it for you in kg, pounds or stone.
What is a healthy BMI?
For adults, 18.5 to 24.9 is the healthy range under WHO categories. 25 to 29.9 is overweight and 30 or more is obese.
Is BMI different for women and men?
The formula and adult ranges are the same. Women usually have more body fat than men at the same BMI, so BMI is only a guide.
Can I use this BMI calculator for children?
It gives the BMI number, but children and teens need a percentile for their age and sex. Use a growth chart or ask a doctor.
How do I find the weight for a target BMI?
Multiply the BMI by your height in metres squared. Switch to the target BMI mode and enter your height and the BMI you want.
Can I enter my weight in stone and pounds?
Yes. Select the United Kingdom or Ireland, or choose UK units, and enter stone and pounds.
Is my information saved?
No. Everything is calculated in your browser and nothing you enter is sent or stored.
About this calculator
Written by Umar Khan. The calculator uses the standard BMI formula and the WHO adult categories. It is a screening tool and not medical advice. Last updated November 12, 2026. Questions or corrections: [email protected].
Written by Umar Khan
Umar Khan is a PhD student in engineering at NTNU, the Norwegian University of Science and Technology, in Norway. Every formula and worked example on this page is shown in full so you can check each result yourself. Corrections are welcome at [email protected].
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For information only, not professional advice.
Written by Umar Khan. Last updated: November 12, 2026.