Breast Cancer Risk Calculator (Gail Model)

Your details

The Gail model applies to women aged 20 to 84 with no personal history of breast cancer, DCIS, or LCIS.
years
Race and ethnicity affect the baseline incidence rates used by the model.
Earlier menarche is associated with a modestly higher lifetime estrogen exposure.
First birth before age 20 carries the lowest risk; nulliparity or first birth at 30+ carries the highest.
Count only mother, sisters, and daughters diagnosed with breast cancer. The Gail model does not account for paternal relatives or ovarian cancer.
Previous biopsies increase risk independently, and the effect is stronger under age 50.
Atypical ductal or lobular hyperplasia found on biopsy roughly doubles risk.
5-year riskAbove-average risk
1.84%

Probability of developing invasive breast cancer in the next 5 years

Average 5-year risk (your age)0.01%
Lifetime risk (to age 90)0.2%
Average lifetime risk0.1%
Relative risk1.36
Risk categoryAbove Average
1.84% %
Average or below<1.67%Above average1.67%-3%High3%+

Your 5-year risk is 1.84%, above the average of 1.35% for your age.

  • Your estimated lifetime risk (to age 90) is 18.9%.
  • Your relative risk is 1.36, meaning your estimated risk is about 1.4x the baseline for your age and race.
  • A 5-year risk at or above 1.67% meets the FDA threshold used in discussions about risk-reducing medications such as tamoxifen, raloxifene, or aromatase inhibitors.
  • This estimate is based on population statistics: it reflects likelihood, not certainty. Genetic factors (BRCA1/BRCA2), dense breast tissue, and hormone use are not fully captured by this model.

Next stepDiscuss these results with your healthcare provider, who can recommend appropriate screening intervals, risk-reduction strategies, or referral for genetic counseling.

 = Powered by OnlyCalculators