This calculator estimates PSA density, which is your PSA divided by the size of your prostate. PSA density helps put a PSA result in context because a larger prostate can raise PSA even without cancer. You can either enter your prostate volume directly or let the tool estimate it from MRI or ultrasound measurements using the standard ellipsoid method. Many clinical pathways use PSA density together with MRI findings to guide whether biopsy is likely to be useful.
Reference points used in this calculator
Risk tiers commonly reported in MRI-era pathways:
Low: < 0.10 ng/mL/cm³
Intermediate: 0.10 to < 0.15 ng/mL/cm³
Higher risk: ≥ 0.15 ng/mL/cm³;
Some protocols treat ≥ 0.20 ng/mL/cm³ as a stronger biopsy signal, especially with a negative or indeterminate MRI.
While 0.15 is still commonly used, newer studies suggest 0.20 fits better when MRI quality is average, and the cutoff can be even higher with a very accurate MRI.
References:
Pellegrino F, Tin AL, Martini A, Vertosick EA, Porwal SP, Stabile A, Gandaglia G, Eastham JA, Briganti A, Montorsi F, Vickers AJ. Prostate-specific Antigen Density Cutoff of 0.15 ng/ml/cc to Propose Prostate Biopsies to Patients with Negative Magnetic Resonance Imaging: Efficient Threshold or Legacy of the Past? Eur Urol Focus. 2023 Mar;9(2):291-297.
Teică RV, Ciofiac CM, Florescu LM, Gheonea IA. Is the Ellipsoid Formula Reliable in Prostate MRI?. Curr Health Sci J. 2023;49(4):530-535.
Benson MC, Whang IS, Olsson CA, McMahon DJ, Cooner WH. The use of prostate specific antigen density to enhance the predictive value of intermediate levels of serum prostate specific antigen. J Urol. 1992;147(3 Pt 2):817-821.