# What is my breast cancer risk?

Estimates a woman’s chance of invasive breast cancer in the next 5 years and by age 90 with the Gail model, as the NCI Breast Cancer Risk Assessment Tool computes it, and the average risk for her age and race.

- Page: https://www.acalculator.org/health/breast-cancer-risk-calculator
- JSON spec: https://www.acalculator.org/health/breast-cancer-risk-calculator.json
- Version: d6b5d2388da3

## Default answer

Example with the default inputs (Past breast cancer, DCIS, LCIS, chest radiation, or a BRCA or other gene change? No, Your age 45, Race or ethnicity White, Age at first period 14 or older, Age at first live birth Under 20, Mother, sisters, or daughters with breast cancer None, Breast biopsies None): The 5-year risk of invasive breast cancer is 0.5% (1% for an average woman of the same age and race).

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| ex | Past breast cancer, DCIS, LCIS, chest radiation, or a BRCA or other gene change? | Whether you have had breast cancer, DCIS or LCIS, radiation to the chest for Hodgkin lymphoma, or carry a gene change such as BRCA1 or BRCA2. The model does not apply then. |
| age | Your age | Your current age in whole years, 35 to 85. |
| race | Race or ethnicity | Race or ethnicity: the model uses different rates and relative risks for each group. |
| men | Age at first period | Your age at your first menstrual period. |
| fb | Age at first live birth | Your age when your first child was born alive, or no births. |
| rel | Mother, sisters, or daughters with breast cancer | How many first-degree relatives (mother, sisters, daughters) have had breast cancer. |
| bx | Breast biopsies | How many breast biopsies you have had (with a benign result). |
| ah | Atypical hyperplasia in a biopsy? | Whether any biopsy showed atypical hyperplasia. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| fiveYear | 5-year risk | The chance of invasive breast cancer in the next 5 years, as a percent, to 1 decimal. |
| fiveYearAverage | Average 5-year risk, same age and race | The 5-year risk of a woman of the same age and race with no risk factors counted, to 1 decimal. |
| lifetime | Risk to age 90 | The chance of invasive breast cancer from now to age 90, as a percent, to 1 decimal. |
| lifetimeAverage | Average risk to age 90, same age and race | The risk to age 90 of a woman of the same age and race with no risk factors counted, to 1 decimal. |

## Method

Gail model: relative risk from age at first period, age at first birth, first-degree relatives, biopsies, and atypical hyperplasia, times race-specific breast cancer rates and (1 − attributable risk), projected year by year with competing mortality.

## Assumptions

- For women 35 to 85 with no history of breast cancer, DCIS, LCIS, chest radiation, or a known gene change.
- Rates and coefficients are those of the NCI BCRA R package 2.1.2, which the NCI tool uses.
- Risks are rounded to 1 decimal, halves up.

## Worked examples

1. ex = no, age = 45, race = white, men = ge14, fb = lt20, rel = 0, bx = 0 gives fiveYear = 0.5%, fiveYearAverage = 1%, lifetime = 6.4%, lifetimeAverage = 11.9%.
2. ex = no, age = 40, race = white, men = 12to13, fb = 25to29, rel = 1, bx = 1, ah = no gives fiveYear = 1.7%, fiveYearAverage = 0.6%, lifetime = 22.6%, lifetimeAverage = 12.4%.
3. ex = no, age = 55, race = black, men = lt12, fb = none, rel = 2+, bx = 2+, ah = yes gives fiveYear = 7.2%, fiveYearAverage = 1.4%, lifetime = 34.7%, lifetimeAverage = 8.1%. Source: BCRA 2.1.2 port (CARE coefficients, Gail 2007): 7.2133%, 1.4109%, 34.7442%, 8.0655%.
4. ex = no, age = 50, race = hispanicUS, men = 12to13, fb = ge30, rel = 1, bx = 0 gives fiveYear = 1.7%, fiveYearAverage = 1.1%, lifetime = 12.7%, lifetimeAverage = 8.9%. Source: BCRA 2.1.2 port (Hispanic, US born, Banegas 2017): 1.6643%, 1.1416%, 12.6504%, 8.8545%.
5. ex = no, age = 60, race = chinese, men = ge14, fb = 20to24, rel = 2+, bx = 1, ah = unknown gives fiveYear = 2.1%, fiveYearAverage = 0.8%, lifetime = 11.5%, lifetimeAverage = 4.7%. Source: BCRA 2.1.2 port (Asian American, Matsuno 2011): 2.0904%, 0.8268%, 11.4886%, 4.6968%.
6. ex = no, age = 70, race = other, men = unknown, fb = unknown, rel = unknown, bx = unknown gives fiveYear = 1.1%, fiveYearAverage = 2.2%, lifetime = 3.3%, lifetimeAverage = 6.3%.

## FAQ

### What is the Gail model?

The Gail model estimates a woman’s chance of invasive breast cancer over a period of time from a few personal facts. Gail and others built it in 1989 from the Breast Cancer Detection Demonstration Project. The National Cancer Institute (NCI) uses an updated version in its Breast Cancer Risk Assessment Tool, with separate versions for Black (CARE), Hispanic, and Asian and Pacific Islander women.

### What does a 5-year risk of 1.5% mean?

Out of 1,000 women with the same answers, about 15 would be expected to develop invasive breast cancer in the next 5 years. The page also shows the risk of an average woman of the same age and race, for comparison.

### Who should not use this calculator?

Women who have had breast cancer, DCIS, or LCIS; who had chest radiation (for example for Hodgkin lymphoma); or who carry a gene change such as BRCA1 or BRCA2. The model underestimates risk in these women, so the page gives no answer. It is also not for women under 35.

### What if I do not know an answer?

Choose Unknown. The model then counts that factor as the lowest-risk answer, as the NCI tool does, so the result may be too low.

### Does the model include breast density or the family history of my father’s side?

No. It counts only mother, sisters, and daughters with breast cancer, and not breast density, other relatives, or age at diagnosis. Other models, which your clinician can use, include more family history.

## Sources

- Gail MH, Brinton LA, Byar DP, et al. Projecting individualized probabilities of developing breast cancer for white females who are being examined annually. J Natl Cancer Inst. 1989;81(24):1879-1886. https://doi.org/10.1093/jnci/81.24.1879
- Costantino JP, Gail MH, Pee D, et al. Validation studies for models projecting the risk of invasive and total breast cancer incidence. J Natl Cancer Inst. 1999;91(18):1541-1548. https://doi.org/10.1093/jnci/91.18.1541
- Gail MH, Costantino JP, Pee D, et al. Projecting individualized absolute invasive breast cancer risk in African American women. J Natl Cancer Inst. 2007;99(23):1782-1792. https://doi.org/10.1093/jnci/djm223
- Matsuno RK, Costantino JP, Ziegler RG, et al. Projecting individualized absolute invasive breast cancer risk in Asian and Pacific Islander American women. J Natl Cancer Inst. 2011;103(12):951-961. https://doi.org/10.1093/jnci/djr154
- Banegas MP, John EM, Slattery ML, et al. Projecting individualized absolute invasive breast cancer risk in US Hispanic women. J Natl Cancer Inst. 2017;109(2):djw215. https://doi.org/10.1093/jnci/djw215
- National Cancer Institute. BCRA: Breast Cancer Risk Assessment, R package version 2.1.2 (absolute.risk.R, relative.risk.R, recode.check.R). https://cran.r-project.org/package=BCRA (retrieved 2026-09-29)
- National Cancer Institute. Breast Cancer Risk Assessment Tool. https://bcrisktool.cancer.gov/ (retrieved 2026-09-29)