BMI calculator for adults

Use the BMI calculator for adults to work out your Body Mass Index.

Healthy Weight Range18.50 - 24.99
Overweight25.00 - 29.99
Obese30 or more


Measuring Body Mass Index

Health professionals commonly measure Body Mass Index (BMI) to assess whether patients are a healthy weight. It measures weight in relation to height to determine BMI category:

  • Normal weight: BMI of 18.5 to 24.9
  • Overweight: BMI of 25 to 29.9
  • Obese: BMI of 30 or higher

Children and teenagers

It's not always easy to tell if a child is a healthy weight for their age and height just by looking at them. Children and teenagers need to grow, and staying within a certain weight range for their age and gender can help support healthy development. For children 2 to 18 years old, use the Children's Weight Status Calculator This is just a guide and should not replace professional health advice. Visit your GP to discuss yours or your child's health and weight.


As your baby grows, it is normal and healthy to gradually gain weight during your pregnancy. The amount of weight you gain during pregnancy can affect your own health as well as your baby's health and development. If you're pregnant, you can use the Pregnancy Weight Gain Calculator to see what your healthy weight gain range during your pregnancy is.

This is just a guide and should not replace professional health advice. Always seek the guidance of your GP or other qualified health professional with any questions about your health or your pregnancy.

What is a healthy weight?

Maintaining a healthy weight has many short and long-term benefits and can help you stay healthier as you grow older. Setting small, specific goals for getting active is the quickest way to change your habits and maintain a healthy weight.

If you're above a healthy weight, you may be at increased risk of health problems including diabetes, heart disease and certain cancers.

Doctors and other health care professionals are the best people to determine whether your weight is healthy. Visit your GP if you'd like to start a conversation about your health or weight.

For more tips, tools and free programs that support healthy eating and active living for you and your family, visit the Healthy Eating Active Living website.

Current as at: Wednesday 10 May 2023
Contact page owner: Centre for Population Health