PSA Density Calculator — PSAD from PSA & Prostate Volume
Calculate PSA Density (PSAD) by dividing serum PSA by prostate volume. A lower PSAD favours benign prostatic hyperplasia; values above 0.15 ng/mL/cc raise concern for prostate cancer and are used to guide biopsy decisions.
ng/mL
mL (cc)
cm
cm
cm
PSA divided by prostate volume — lower values favour benign cause
- 1
Prostate volume
35 - 2
PSA Density
4.5 ÷ 35 = 0.129
How does this calculator work?
PSA Density = PSA (ng/mL) ÷ prostate volume (mL). Values < 0.10 ng/mL/cc favour benign disease; > 0.15 raises concern for cancer and often warrants biopsy consideration. Prostate volume from TRUS/MRI can also be calculated here as 0.523 × L × W × H.
Formula
How this is calculated
PSA (prostate-specific antigen) rises in both prostate cancer and benign prostatic hyperplasia (BPH). Larger prostates naturally produce more PSA, so an elevated PSA in a large gland may not indicate cancer. PSA density normalises PSA for gland size: PSAD = PSA (ng/mL) ÷ prostate volume (mL or cc). A PSAD below 0.10 ng/mL/cc is generally considered reassuring; above 0.15 ng/mL/cc, the contribution of cancer to PSA elevation becomes more likely and biopsy is typically considered.
Prostate volume is measured by transrectal ultrasound (TRUS) or MRI using the prolate-spheroid approximation: V = 0.523 × length × width × height (cm³), where 0.523 ≈ π/6. Enter the volume directly if your imaging report gives it, or enter the three axial dimensions to compute it. Volumes measured by different modalities (TRUS vs. MRI) may differ slightly.
PSAD is an adjunct to clinical assessment, not a standalone diagnostic. It performs better in the PSA grey zone (4–10 ng/mL) than at very high PSA levels. Other factors — patient age, PSA velocity, free/total PSA ratio, digital rectal examination, family history and ethnicity — must all be considered. Always discuss results with a qualified urologist or healthcare provider.
Frequently asked questions
Most urological guidelines use 0.15 ng/mL/cc as the clinically significant threshold. Values below 0.10 are generally considered low risk, 0.10–0.15 intermediate, and above 0.15 associated with a higher probability of significant prostate cancer. These thresholds are guidelines, not absolutes, and vary by guideline body and clinical context.
PSA is produced by both normal and cancerous prostate tissue. A man with a 100 mL prostate due to BPH will naturally have a higher PSA than one with a 20 mL gland, even with no cancer. Correcting for volume (i.e., computing density) improves the specificity of PSA testing for detecting cancer, reducing unnecessary biopsies in men with large but benign glands.
Prostate volume is most commonly determined by transrectal ultrasound (TRUS) or multiparametric MRI (mpMRI), both of which measure the three axial dimensions. The prolate-spheroid formula V = 0.523 × L × W × H (cm³) is standard. MRI tends to give slightly larger estimates than TRUS. The volume from the imaging report can be entered directly into this calculator.
Also known as
TG we-Calculate Editorial Team. (2026). PSA Density Calculator — PSAD from PSA & Prostate Volume [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/psa-density-calculator
TG we-Calculate Editorial Team. "PSA Density Calculator — PSAD from PSA & Prostate Volume." TG we-Calculate. 2026. https://we-calculate.com/calculator/psa-density-calculator.
TG we-Calculate Editorial Team, "PSA Density Calculator — PSAD from PSA & Prostate Volume," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/psa-density-calculator
@misc{wecalculate_psa_density_calculator, title = {PSA Density Calculator — PSAD from PSA & Prostate Volume}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/psa-density-calculator}}, year = {2026}, note = {TG we-Calculate} }
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