Español
PDFs by language
Our 24/7 cancer helpline provides support for people dealing with cancer. We can connect you with trained cancer information specialists who will answer questions about a cancer diagnosis and provide guidance and a compassionate ear.
Chat live online
Select the Live Chat button at the bottom of the page
At our National Cancer Information Center trained Cancer Information Specialists can answer questions 24 hours a day, every day of the year to empower you with accurate, up-to-date information to help you make educated health decisions. We connect patients, caregivers, and family members with valuable services and resources.
Or ask us how you can get involved and support the fight against cancer. Some of the topics we can assist with include:
For medical questions, we encourage you to review our information with your doctor.
Body mass index, or BMI, is one way to look at whether a person is at a healthy weight. BMI is a number based on height and weight. It can be used to place a person in categories ranging from underweight to obese.
But BMI doesn’t work well for everybody. There are other things to think about when deciding how much someone should weigh. If you have a BMI outside the normal range, your health care provider might also look at skinfold thickness (a measure of body fat), waist size, evaluations of your diet and family health problems, blood sugar levels, and other factors to find out if your weight might pose a health risk. To learn more about BMI and how extra body weight can affect your risk of cancer, see Body Weight and Cancer Risk.
Enter your height and weight below to find your body mass index (BMI)
Your BMI is
Underweight
Below 18.5
Normal weight
18.5-24.9
Overweight
25-29.9
Obese
30 and higher
Note: The BMI may not be accurate for people with greater muscle mass (such as athletes) or in older people and others who have lost muscle mass.
If you are overweight or obese, even a small weight loss (10% of your current weight) can lower your risk of several diseases. People who are overweight or obese have a greater chance of developing several types of cancer—including colorectal cancer and breast cancer (for women past menopause)—as well as high blood pressure, high blood cholesterol or other lipid disorders, diabetes, heart disease, and stroke.
Being very underweight – especially if you’ve had rapid or unintentional weight loss – can also be a sign of health problems.