How We Calculate Your Risk

How we turn your details into a clear, personalised risk estimate to guide the right screening plan.

A hand holding a glowing, sparkling DNA double helix model against a dark background.

The model we use

We use the IBIS (Tyrer–Cuzick) model, a widely‑validated tool used internationally. It estimates your year‑by‑year risk (for the next 20 years) and your lifetime risk (to age 85). It also estimates the probability of carrying a BRCA1/BRCA2 mutation—information that can guide genetic testing.

Silhouette of a woman with six icons around her representing a calendar, DNA, flowchart, gauge, money, and a phone headset. The first step in personalised breast screening is accurate risk assessment.

What the model considers

  • Your age, personal health and hormonal factors (e.g., age at first period/first birth)

  • Relevant breast biopsy results

  • Family history

  • Breast density

Who the calculator is (and isn’t) for

Our online tool is designed for women 18–75 who have not had breast cancer and have not had both breasts removed. It does not apply to men, to people with known gene changes other than BRCA1/2, or to those who have had chest radiotherapy. If you’re unsure, start the form and we’ll guide you, or contact our team.

CALCULATE YOUR BREAST CANCER RISK