Prostate Health Index (phi)
Prostate Health Index (phi; Catalona 2011): phi = (p2PSA / free PSA) x sqrt(total PSA), with p2PSA ([-2]proPSA) in pg/mL and free/total PSA in ng/mL.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Total PSA
- 4 ng/mL
- Free PSA
- 0.5 ng/mL
- p2PSA / [-2]proPSA
- 12 pg/mL
Result: phi 48 — about 33% probability of prostate cancer on biopsy.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Reference
- total PSA 2-10 ng/mL, normal DRE: phi 0-26.9 ~11%, 27-35.9 ~21%, 36-54.9 ~33%, >= 55 ~50% cancer on biopsy (approximate).
What you enter
- Total PSA (ng/mL)
- Free PSA (ng/mL)
- p2PSA / [-2]proPSA (pg/mL)
How this is calculated
- Formula
- phi = (p2PSA / free PSA) x sqrt(total PSA); p2PSA in pg/mL, free/total PSA in ng/mL.
Catalona WJ, Partin AW, Sanda MG, et al. A multicenter study of [-2]pro-prostate specific antigen combined with prostate specific antigen and free PSA for prostate cancer detection in the 2.0 to 10.0 ng/mL PSA range. J Urol. 2011;185(5):1650-1655. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.