This tool calculates your percent-free PSA using your total and free PSA values. It provides a research-backed interpretation of your result, helping you understand whether your levels suggest a higher or lower risk of prostate cancer. The calculator is most accurate for men with total PSA between 4 and 10 ng/mL. It does not replace medical advice. Always consult your doctor for personalized assessment.
Research shows that a % free PSA of ≤10% is linked to a higher chance of cancer, especially when total PSA is between 4–10 ng/mL. A value above 25% is generally associated with a lower risk, while 10–25% falls into an intermediate range where other factors (like imaging or prostate size) should be considered. These ranges come from large clinical studies and are commonly used by urologists to guide decisions about further testing.
References:
- Catalona WJ, Partin AW, Slawin KM, et al. Use of the percentage of free prostate-specific antigen to enhance differentiation of prostate cancer from benign prostatic disease: a prospective multicenter clinical trial. JAMA. 1998;279(19):1542-1547.
- Yilmaz H, Ciftci S, Yavuz U, Ustuner M, Saribacak A, Dillioglugil O. Percentage of free prostate-specific antigen (PSA) is a useful method in deciding to perform prostate biopsy with higher core numbers in patients with low PSA cut-off values. Kaohsiung J Med Sci. 2015;31(6):315-319.
- American Cancer Society. Prostate Cancer Screening Tests. 2023. https://www.cancer.org/cancer/types/prostate-cancer/detection-diagnosis-staging/tests.html