Health calculators

Breast Cancer Risk Calculator

Updated Jul 16, 2026 By Jehan Wadia
Rate Formulas Medical disclaimer
Eligibility Screening
Ever diagnosed with invasive breast cancer?
Diagnosed with DCIS or LCIS?
Tested positive for a BRCA1 or BRCA2 mutation?
Chest radiation therapy before age 30?
About You
Between 25 and 90 years.
Adjusts the population baseline incidence rate.
Ashkenazi Jewish Heritage
Measurement Units:
Feet
Inches
Reproductive & Menstrual History
Have you given birth?
Menopause status
Biopsy & Breast Density
Breast biopsy history
Breast density (BI-RADS)
Family History
Mother, sisters, or daughters.
Grandmothers, aunts, half-sisters.
Any relative with bilateral breast cancer?
Ovarian cancer in the family?
Your Estimated Risk
5-Year Risk of Invasive Breast Cancer
2.7%
Average for your age group: 1.1%
Above Average
About 3 out of 100 women with your profile are expected to develop breast cancer over the next 5 years.
Lifetime Risk (to age 90)
18.5%
Average for your age group: 9.8%
Above Average
About 19 out of 100 women with your profile are expected to develop breast cancer in their lifetime.
Risk calculated using the Gail Model with Tyrer-Cuzick (IBIS) adjustments.
You vs. Average Comparison
MeasureYour RiskAverage for Age
Suggested Next Steps
Step-by-Step Solution

Introduction

This Breast Cancer Risk Calculator estimates your chance of developing invasive breast cancer over the next 5 years and over your lifetime. It uses the Gail Model along with Tyrer-Cuzick adjustments — two well-known methods trusted by doctors and researchers.

The tool asks about your age, family history, reproductive history, breast density, and other health factors. It then uses these details to calculate a risk score and compares it to the average risk for women your age. You will also see a step-by-step breakdown of how your result was calculated.

This calculator is designed for women aged 25 to 90 who have not been diagnosed with invasive breast cancer, DCIS, LCIS, or a BRCA gene mutation. If any of these apply to you, the tool will let you know that these models are not validated for your situation.

This tool does not diagnose cancer. It gives an estimate based on statistical models. Your actual risk may be higher or lower. Always share your results with your doctor so they can help you decide on the right screening plan for you.

How to Use Our Breast Cancer Risk Calculator

Enter your health, family, and reproductive details below. The calculator will estimate your 5-year and lifetime risk of developing invasive breast cancer and compare it to the average for your age group.

Eligibility Screening

Prior breast cancer diagnosis: Select whether you have ever been diagnosed with invasive breast cancer. If yes, this tool does not apply to you.

DCIS or LCIS diagnosis: Select whether you have been diagnosed with ductal or lobular carcinoma in situ. If yes, this tool is not validated for your situation.

BRCA1 or BRCA2 mutation: Select whether you have tested positive for a BRCA gene mutation. If yes, you should work with a genetic counselor instead of using this tool.

Chest radiation before age 30: Select whether you received radiation therapy to the chest area before turning 30. If yes, this calculator cannot give you an accurate result.

About You

Current age: Enter your age in years. You must be between 25 and 90 years old to use this calculator. If you need to determine your exact age from your date of birth, our Age Calculator can help.

Race or ethnicity: Choose the group that best describes you. This adjusts the baseline cancer rate used in the calculation, since rates differ across populations.

Ashkenazi Jewish heritage: Select yes, no, or unknown. Ashkenazi Jewish ancestry is linked to a higher background rate of certain gene mutations that affect breast cancer risk.

Measurement units: Choose Imperial (feet, inches, pounds) or Metric (centimeters, kilograms) for your height and weight entries.

Height: Enter your height in feet and inches, or in centimeters if you chose metric units.

Weight: Enter your weight in pounds, or in kilograms if you chose metric units. Height and weight are used to calculate your BMI, which can affect risk after menopause.

Reproductive and Menstrual History

Age at first menstrual period: Select the age when you had your first period. An earlier start is linked to a slightly higher risk.

Have you given birth: Select yes or no. If yes, you will be asked your age at your first live birth.

Age at first live birth: If you have given birth, select the age range when you had your first baby. Having a first child at a younger age is linked to lower risk.

Menopause status: Select whether you are premenopausal, perimenopausal, postmenopausal, or unsure. If postmenopausal, you will be asked the age when menopause began.

Age at menopause: If you are postmenopausal, enter the age when your periods stopped for 12 or more months.

Hormone Replacement Therapy (HRT): Select whether you have never used HRT, used it in the past, or currently use estrogen-only or combined estrogen-plus-progestin therapy. Current combined HRT raises risk the most.

Biopsy and Breast Density

Breast biopsy history: Select whether you have had a breast biopsy and, if so, what the result showed. If you have had a biopsy, you will be asked how many and whether atypical cells were found.

Atypical Ductal Hyperplasia (ADH): If you have had a biopsy, check this box if atypical ductal hyperplasia was found. ADH raises breast cancer risk significantly.

Number of previous biopsies: If you have had a biopsy, enter the total number. More biopsies can indicate higher risk.

Breast density (BI-RADS): Select your breast density category from your most recent mammogram report. Denser breast tissue is linked to higher risk. Choose "Not reported / Unknown" if you do not have this information.

BRCA genetic test result: Select whether you have not been tested or tested negative. A negative result slightly lowers your calculated risk.

Family History

First-degree relatives with breast cancer: Select how many of your mother, sisters, or daughters have been diagnosed with breast cancer. More affected relatives means higher risk.

Second-degree relatives with breast cancer: Select how many of your grandmothers, aunts, or half-sisters have been diagnosed with breast cancer.

Relative with bilateral breast cancer: Select yes if any family member has had breast cancer in both breasts.

Ovarian cancer in the family: Select yes if any close family member has been diagnosed with ovarian cancer. This can signal a shared genetic risk.

Your Results

Press the Calculate button to see your estimated 5-year and lifetime breast cancer risk, a comparison chart against the average for your age, a suggested action plan, and a full step-by-step breakdown of the math behind your result. Use the Reset button to clear all fields, or the Print button to save a copy of your results.

Breast Cancer Risk Calculator

This calculator estimates your chance of getting invasive breast cancer. It gives you two numbers: your risk over the next 5 years and your risk over your lifetime (up to age 90). It also shows how your risk compares to the average woman your age.

The tool uses the Gail Model, a well-known method developed by the National Cancer Institute. It also applies adjustments based on the Tyrer-Cuzick (IBIS) model to account for extra factors like breast density, hormone therapy use, body weight, and extended family history. Together, these give a more complete picture of your personal risk.

What Information You Need

The calculator asks about your age, race, menstrual history, whether you have had children, breast biopsy results, breast density from a mammogram, and how many close family members have had breast or ovarian cancer. Each of these factors is known to raise or lower breast cancer risk by a measurable amount. Your height and weight are also used to compute your BMI, which influences postmenopausal risk. If you are unsure of your current BMI, you can check it with our dedicated BMI Calculator.

Who This Tool Is For

This calculator is designed for women ages 25 to 90 who have not been diagnosed with breast cancer, DCIS, or LCIS. It also does not apply to women who carry a known BRCA1 or BRCA2 gene mutation or who received chest radiation before age 30. If any of these apply to you, your doctor or a genetic counselor can give you a better assessment.

What Your Results Mean

A higher number does not mean you will get breast cancer. It means your chance is higher than some other women. A lower number does not mean you are safe from it. The result is a statistical estimate, not a diagnosis. If your lifetime risk is 20% or more, doctors often call that high risk, and you may qualify for extra screening like breast MRI along with yearly mammograms. Share your results with your doctor so you can make a screening plan that fits your situation.

If you are interested in assessing other aspects of your long-term health, you may also find our ASCVD Risk Calculator or Framingham Risk Calculator helpful for evaluating cardiovascular disease risk. Our Life Expectancy Calculator can also give you a broader perspective on overall health planning. For women who are currently managing their weight as part of a risk-reduction strategy, tools like the Calorie Calculator, TDEE Calculator, and Ideal Body Weight Calculator can support healthy lifestyle goals. Tracking metrics such as your body fat percentage and waist-to-hip ratio may also be useful, since maintaining a healthy body composition is one of the modifiable factors linked to lower breast cancer risk.

Formulas used

Gail Model Linear Predictor
LP = \beta_{\text{men}} \, c_{\text{men}} + \beta_{\text{biop}} \, c_{\text{biop}} + \beta_{\text{AFLB}} \, c_{\text{AFLB}} + \beta_{\text{rel}} \, c_{\text{rel}} + \beta_{\text{int}} \left( c_{\text{AFLB}} \cdot c_{\text{rel}} \right)
Gail Relative Risk
RR = e^{\,LP} \times AH
Age-Specific Breast Cancer Hazard
\lambda_1(t) = h_1(t) \times r_{\text{race}} \times (1 - AR) \times RR
Absolute Risk with Competing Mortality (Gail)
R = \sum_{t=a}^{a+n} \frac{\lambda_1(t)}{\lambda_1(t)+\lambda_2(t)} \left(1 - e^{-(\lambda_1(t)+\lambda_2(t))}\right) \exp\!\left(-\sum_{u < t}\left[\lambda_1(u)+\lambda_2(u)\right]\right)
Tyrer-Cuzick Adjustment Multiplier
M = f_{\text{density}} \times f_{\text{HRT}} \times f_{\text{BMI}} \times f_{\text{2nd-deg}} \times f_{\text{ovarian}} \times f_{\text{bilateral}} \times f_{\text{Ashkenazi}} \times f_{\text{BRCA}}
Final Adjusted Risk
R_{\text{final}} = R_{\text{Gail}} \times M
Body Mass Index
BMI = \frac{703 \times W_{\text{lb}}}{H_{\text{in}}^{\,2}} = \frac{W_{\text{kg}}}{\left(\dfrac{H_{\text{cm}}}{100}\right)^{2}}

Frequently asked questions

What is the Gail Model?

The Gail Model is a math tool made by the National Cancer Institute. It uses your age, race, family history, biopsy results, and reproductive history to estimate your chance of getting breast cancer. Doctors have used it since 1989. It is one of the most studied and trusted breast cancer risk models in the world.

What are Tyrer-Cuzick adjustments?

The Tyrer-Cuzick model (also called the IBIS model) looks at extra risk factors that the Gail Model does not cover on its own. These include breast density, hormone replacement therapy, body weight, second-degree family history, and ovarian cancer in the family. This calculator applies Tyrer-Cuzick multipliers on top of the Gail score to give you a more complete risk estimate.

What does 5-year risk mean?

Your 5-year risk is the chance that you will develop invasive breast cancer within the next 5 years. For example, a 5-year risk of 2% means that about 2 out of 100 women with your same profile would be expected to get breast cancer in that time.

What does lifetime risk mean?

Lifetime risk is your estimated chance of developing invasive breast cancer from your current age up to age 90. It covers a much longer time period than the 5-year risk, so the number is usually higher.

Can men use this breast cancer risk calculator?

No. This calculator was built using data from women only. The Gail and Tyrer-Cuzick models are not validated for men. Men can get breast cancer, but it is rare, and risk assessment for men requires a different approach. If you are a man concerned about breast cancer, talk to your doctor.

Why does the calculator ask about race and ethnicity?

Breast cancer rates differ across racial and ethnic groups. The baseline incidence data used in the Gail Model comes from population studies that tracked these differences. Choosing your race or ethnicity lets the calculator use the correct baseline rate for your group, which makes your result more accurate.

What is breast density and how do I find mine?

Breast density describes how much fibrous and glandular tissue you have compared to fatty tissue. It is rated on a scale from A (mostly fatty) to D (extremely dense). You can find your breast density category on your mammogram report. If you have never had a mammogram or your report does not list it, choose Not reported / Unknown.

Why does breast density affect my risk?

Women with dense breast tissue (BI-RADS C or D) have a higher chance of developing breast cancer than women with fatty breast tissue. Dense tissue also makes it harder to spot tumors on a mammogram. That is why breast density is an important factor in risk calculations.

What is atypical ductal hyperplasia (ADH)?

ADH is a condition found on a breast biopsy. It means some cells in the milk ducts look abnormal but are not cancer. Having ADH raises your breast cancer risk significantly. If a biopsy found ADH, check the ADH box in the calculator to get a more accurate result.

Does hormone replacement therapy increase breast cancer risk?

Yes. Studies show that current use of combined estrogen-plus-progestin HRT raises breast cancer risk the most. Estrogen-only HRT raises risk by a smaller amount. Past use has a very small effect. The calculator adjusts your score based on which type of HRT you use, if any.

Why does my weight matter for breast cancer risk?

After menopause, extra body fat can raise estrogen levels, which increases breast cancer risk. The calculator uses your height and weight to figure out your BMI. If you are postmenopausal and your BMI is 25 or higher, the tool applies a small increase to your risk score.

What counts as a first-degree relative?

A first-degree relative is your mother, a sister, or a daughter. These are the closest blood relatives. Having one or more first-degree relatives with breast cancer raises your own risk. The calculator asks how many of these relatives have been diagnosed.

What counts as a second-degree relative?

A second-degree relative includes grandmothers, aunts, and half-sisters. They share less DNA with you than first-degree relatives, but their cancer history still affects your risk. The calculator applies a smaller adjustment for second-degree relatives compared to first-degree ones.

What does it mean if I am not eligible?

If you answer yes to any eligibility question — such as a prior breast cancer diagnosis, DCIS, LCIS, a BRCA mutation, or chest radiation before age 30 — the calculator cannot give you an accurate result. The Gail and Tyrer-Cuzick models were not built for these situations. You should talk to your doctor or a genetic counselor for a proper risk assessment.

Is a high risk score the same as a cancer diagnosis?

No. A high risk score does not mean you have cancer or that you will get cancer. It means your chance is higher than average based on your risk factors. Many women with high scores never develop breast cancer. The result is a statistical estimate, not a diagnosis.

What should I do if my lifetime risk is 20% or higher?

A lifetime risk of 20% or more is considered high risk by most medical guidelines. You should share your results with your doctor. They may recommend extra screening such as a yearly breast MRI in addition to a mammogram. You may also be a candidate for risk-reducing medication or genetic counseling.

Can I lower my breast cancer risk?

Some risk factors like age and family history cannot be changed. But you can lower your risk by keeping a healthy weight, staying active, limiting alcohol, and avoiding long-term combined hormone therapy. Talk to your doctor about steps that make sense for your situation.

Why does age at first period affect risk?

Starting your period at a younger age means your body is exposed to estrogen for a longer time over your life. Longer estrogen exposure is linked to a higher chance of breast cancer. That is why the calculator asks when your periods began.

Why does having children affect risk?

Having your first child at a younger age is linked to lower breast cancer risk. Pregnancy changes breast cells in a way that may protect them. Women who have never given birth have a slightly higher risk than women who had their first child before age 20.

What does Ashkenazi Jewish heritage have to do with breast cancer?

People of Ashkenazi Jewish descent have a higher rate of BRCA1 and BRCA2 gene mutations. Even if you have not been tested for these mutations, having this heritage slightly raises your statistical risk. The calculator applies a small adjustment if you select yes.

How accurate is this calculator?

The Gail Model has been validated in large studies and is well-calibrated for groups of women. It is good at predicting how many women in a group will get breast cancer. However, it is less precise at predicting whether one specific person will or will not get cancer. No risk calculator is perfect. Use your result as a starting point for a conversation with your doctor.

Can I save or print my results?

Yes. Click the Print button to open your browser's print window. You can print a paper copy or save it as a PDF. The form fields are hidden during printing so only your results are shown.

How often should I recalculate my risk?

It is a good idea to recalculate your risk every 1 to 2 years or whenever your health changes. For example, update your results after menopause, after a new biopsy, or if a close family member is diagnosed with breast or ovarian cancer.

Does a negative BRCA test mean I have no genetic risk?

No. A negative BRCA1/BRCA2 test means you do not carry those specific mutations. But other genes can also raise breast cancer risk. A negative BRCA result slightly lowers your calculated score, but it does not remove all genetic risk. If you have a strong family history, talk to a genetic counselor about broader testing.

What is the difference between DCIS and invasive breast cancer?

DCIS (ductal carcinoma in situ) is an early, non-invasive form of breast cancer where abnormal cells are only inside the milk ducts. Invasive breast cancer means the cancer has grown beyond the ducts into nearby tissue. This calculator estimates risk for invasive breast cancer only.

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