Cancer Risk Calculator

Cancer risk is the chance of developing cancer over a period of time. Some of it comes from things you cannot change, like age and genes, and some from things you can, like smoking, alcohol and body weight. This calculator looks at the factors you can change and checks each one against a published guideline, instead of folding your answers into one number.

What This Cancer Risk Calculator Measures

It shows how your habits compare with cancer prevention guidelines, factor by factor, plus your family history. It does not test for cancer or give your personal chance of getting it. In US adults aged 30 and older, about 40% of cancer cases and 44% of cancer deaths in 2019 were linked to factors like these¹.

The Formula

There is no single formula. Each factor has its own measure and cut point:

Pack-years = (cigarettes per day / 20) x years smoked

BMI = weight in kg / (height in m x height in m)

Activity minutes per week = moderate minutes + (2 x vigorous minutes)

Alcohol = drinks on a drinking day, compared with 1 for women or 2 for men

The weight, activity, diet and alcohol targets come from the American Cancer Society (ACS) guideline for cancer prevention².

How This Calculator Computes Your Result

Enter your age and sex at birth, then answer any of the lifestyle sections. Skipped sections show "Not answered" and are not counted. Height and weight work in metric or imperial units, BMI and pack-years are rounded to 1 decimal place, and alcohol is counted in US standard drinks (14 g of alcohol each). The result shows how many answered factors are on track and which to work on first, ordered by how many US cancer cases each is linked to. Your age, sex at birth and smoking history decide which screenings are listed. Nothing is added into an overall percentage.

What Your Result Means

Each factor gets one of four labels:

What "on track" means for each factor, with the share of US cancer cases linked to it:

The case shares come from an ACS analysis of 2019 US data¹. They overlap, because many people have more than one factor, so they cannot be added up. The ACS says it is best not to drink alcohol, and that people who drink should have no more than 1 drink a day for women or 2 for men². It advises 150 to 300 moderate or 75 to 150 vigorous activity minutes a week².

Which Cancer Screenings Apply at Your Age

The calculator lists the US Preventive Services Task Force (USPSTF) screenings for people at average risk:

The rows follow the current USPSTF statements³ ⁴ ⁵ ⁶ ⁷. Cervical screening is usually not needed after a hysterectomy that removed the cervix⁵, and the USPSTF recommends against PSA screening at 70 and older⁷. These ages do not apply to people with a known inherited gene change, a past cancer or other high-risk conditions.

Why Smoking, Weight and Alcohol Lead the List

Cigarette smoking is the largest single factor, behind 19.3% of US cancer cases and 28.5% of cancer deaths¹. Excess body weight and alcohol come next, at 7.6% and 5.4% of cases¹. All cervical cancers and about 92% of skin melanomas are linked to factors that can be changed, mainly HPV infection and UV light¹. That is why vaccines and sunburn are on the list. The CDC recommends HPV vaccination at 11 or 12, with catch-up doses through age 26, and a shared decision with a clinician for some adults 27 to 45⁸.

Family History and Next Steps

About 5% to 10% of cancers are caused by harmful gene changes passed down in families⁹. A family history is still worth noting, because the screening ages above are set for people at average risk³ ⁴. Cancer diagnosed at a young age, such as colon cancer before 50, or cancer in several relatives can be a sign of an inherited cancer syndrome⁹. The calculator flags these patterns.

For a closer look at one cancer, try the Breast Cancer Risk Calculator, Ovarian Cancer Risk Calculator, Lung Cancer Risk Calculator or Prostate Cancer Risk Calculator.