This talk will provide a brief review of the major risk factors for breast cancer and then focus on how they can be combined to create a risk estimate for a woman without breast cancer. The new additions to the Tyrer-Cuzick model will be discussed, notably mammographic breast density and the use of a polygenic risk score based on a panel of common single nucleotide polymorphisms which individually have a small impact on risk but when used as a panel provide useful discrimination. Analyses based on several large cohorts will be presented to illustrate its use. The talk will close with a review of the potential uses of such a model, both for risk adapted screening strategies and selection of high women most likely to benefit from preventive therapy.