- Enter the patient's age — required for age-adjusted reference ranges (40–49: ≤2.5, 50–59: ≤3.5, 60–69: ≤4.5, 70–79: ≤6.5, 80+: ≤7.2 ng/mL).
- Enter Total PSA (required) and optionally Free PSA and Prostate Volume (from TRUS or bladder scan).
- For PSA velocity, enter Prior PSA value and its date, plus the current PSA date (leave blank for today).
- Select the current 5-ARI medication — finasteride (×2 correction) or dutasteride (×2.5 correction) are applied automatically.
- Check any confounding factors that may have falsely elevated PSA before the draw.
- Click Calculate & Interpret to see drug-corrected PSA, all metrics, risk stratification, and recommendations.
All computation runs in your browser — no values are stored or transmitted.
When to Use
Use this calculator for any man undergoing PSA-based prostate cancer screening or monitoring, especially when the clinical picture requires more than a single total PSA value. It is most valuable in three scenarios:
5-ARI drug correction — the most critical use case
Men on finasteride 5 mg or dutasteride 0.5 mg (for BPH or hair loss) have PSA suppressed by 50–70% after ≥6 months of therapy. A raw PSA of 2.0 ng/mL on dutasteride represents a corrected (true) PSA of ~5.0 ng/mL — clearly in the elevated range. Without correction, up to half of significant cancers in this group may be missed. Always apply the correction multiplier and use the corrected PSA for all risk decisions.
Gray zone PSA (4–10 ng/mL)
Total PSA in the 4–10 ng/mL range carries roughly a 25% prostate cancer risk on biopsy — but BPH and prostatitis account for the other 75%. % Free PSA, PSA density, and PSA velocity help separate benign from malignant causes before proceeding to biopsy. Free PSA <10% strongly favors cancer; ≥25% favors benign. PSA density ≥0.15 ng/mL/mL supports biopsy even with borderline total PSA.
Serial PSA monitoring
Enter a prior PSA value and date to compute annualized PSA velocity. A velocity ≥0.75 ng/mL/year — even with an absolute PSA below the biopsy threshold — is independently associated with prostate cancer risk and cancer-specific mortality. Use this feature to detect accelerating PSA rise before the threshold is crossed.
Pearls & Pitfalls
% Free PSA is most useful in the gray zone
The ratio of free-to-total PSA adds meaningful discrimination specifically when total (corrected) PSA is between 4 and 10 ng/mL. Below 4 ng/mL or above 10 ng/mL it adds less incremental value. Order free PSA whenever the corrected total PSA sits in this gray zone and you need to decide about biopsy.
PSA density requires an accurate prostate volume
PSA density = Total PSA ÷ Prostate volume (mL). A threshold of ≥0.15 ng/mL/mL is the standard biopsy trigger. Volume must come from TRUS (most accurate) or bladder scan — DRE estimation is unreliable. PSA density is particularly useful when PSA is mildly elevated and the gland is enlarged (large BPH may explain the PSA without cancer).
Confounders must be resolved before acting
PSA can be transiently elevated by DRE (within 48 hours), prostate biopsy (up to 6 weeks), urethral catheterization (within 1 week), active UTI or prostatitis, ejaculation (within 48 hours), and vigorous perineal pressure (cycling). If any confounders were present before the PSA draw, flag the result and repeat in 4–6 weeks after resolution before making biopsy decisions.
Pitfalls
- 5-ARI correction is mandatory — uncorrected PSA on 5-ARI is the single most common clinical error. Even a "normal" raw PSA may represent a doubled or 2.5× true PSA.
- Alpha-1 blockers do not lower PSA — tamsulosin and silodosin have no meaningful effect on PSA and require no correction.
- Daily tadalafil 5 mg has negligible PSA effect; no numeric correction is applied, but document it in the record.
- PSA alone does not diagnose cancer — all positive results require confirmatory evaluation (mpMRI, biopsy) and physician assessment before treatment decisions.
PSA Panel Calculator
Enter Laboratory Values Interactive
Enter your lab values below. Drug corrections and risk stratification are applied automatically. All fields except Total PSA are optional.
Interpretation Results
| Metric | Result & Interpretation |
|---|---|
| Reported PSA | — |
| Effective PSA | — |
| Age-Adjusted Range | — |
Next Steps
Use the result to support — not replace — clinical judgment. The interpretation is a starting point; final decisions require the full clinical picture.
- If confounders were present: Repeat PSA in 4–6 weeks after complete resolution before making any biopsy or referral decisions.
- If on 5-ARI: Always use the corrected PSA for all cancer-risk decisions. Document the drug, dose, and duration of therapy in the medical record.
- If PSA is in the gray zone (4–10 ng/mL): Order Free PSA and prostate volume if not already done. PSA density ≥0.15 supports biopsy; % Free PSA <10% strongly favors cancer. Consider mpMRI before biopsy — it reduces unnecessary procedures (EAU 2024, NICE 2019).
- If PSA >10 ng/mL or rapidly rising: Refer to urology promptly. Do not delay pending a repeat PSA. Bone scan and mpMRI should be discussed.
- For serial monitoring: Low risk — every 1–2 years. Elevated or borderline — every 6–12 months. After starting a 5-ARI — recheck at 6 months to establish a new treated baseline, then use that value as the comparator (not the pre-treatment PSA).
- Document shared decision-making: PSA screening is a shared decision between patient and physician. Discuss the benefits and limitations, life expectancy, and individual risk factors (family history, prior biopsy) before any screening or re-screening decision.
Evidence & References
Age-Adjusted PSA Reference Ranges
Age-specific PSA norms (Oesterling JE, et al. JAMA 1993) were derived from a community cohort of men without prostate disease. They improve sensitivity in younger men and reduce unnecessary biopsies in older men with BPH.
| Age Group | Upper Reference Limit | Clinical Implication |
|---|---|---|
| 40–49 years | ≤ 2.5 ng/mL | PSA above this in a young man warrants evaluation regardless of absolute value |
| 50–59 years | ≤ 3.5 ng/mL | Most common screening age; use with free PSA in the gray zone |
| 60–69 years | ≤ 4.5 ng/mL | BPH becomes common; PSA density helps distinguish |
| 70–79 years | ≤ 6.5 ng/mL | Large prostates common; individualize biopsy decisions |
| 80+ years | ≤ 7.2 ng/mL | Shared decision-making with life expectancy context |
5-ARI Correction Factors
Finasteride 5 mg (a type-2 5-ARI) suppresses serum PSA by approximately 50% after ≥6 months of therapy (Oesterling JE, et al. Urology 1993). Dutasteride 0.5 mg (a dual type 1+2 5-ARI) suppresses PSA by 50–70% (Andriole GL, et al. Eur Urol 2010). Current AUA and EAU guidelines recommend doubling PSA for finasteride and multiplying by 2.5 for dutasteride as conservative correction factors. Apply the correction to PSA drawn after ≥6 months of therapy; earlier draws reflect incomplete suppression.
% Free PSA Thresholds
In men with total PSA 4–10 ng/mL and a non-suspicious DRE, % Free PSA refines cancer risk (Catalona WJ, et al. JAMA 1998):
- <10% — cancer probability ~56%; biopsy strongly recommended
- 10–15% — cancer probability ~28%; biopsy generally recommended
- 15–25% — cancer probability ~16%; individualize (PSA density, velocity, age, family history)
- ≥25% — cancer probability <8%; watchful waiting appropriate if other factors favorable
PSA Velocity
An annual PSA rise ≥0.75 ng/mL/year (in men with PSA >4 ng/mL) is independently associated with prostate cancer risk and cancer-specific mortality (Carter HB, et al. JAMA 1992). Velocity requires at least two measurements over ≥18 months for reliable calculation. A rapid rise even within the "normal" range warrants evaluation.
Key References
- Oesterling JE, Jacobsen SJ, Chute CG, et al. Serum prostate-specific antigen in a community-based population of healthy men. JAMA. 1993;270(7):860–864.
- 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. JAMA. 1998;279(19):1542–1547.
- Carter HB, Morrell CH, Pearson JD, et al. Estimation of prostatic growth using serial prostate-specific antigen measurements in men with and without prostate disease. Cancer Res. 1992;52(12):3323–3328.
- European Association of Urology (EAU). Guidelines on Prostate Cancer. Edn. presented at the EAU Annual Congress Paris 2024. EAU Guidelines Office, Arnhem, The Netherlands.
- American Urological Association (AUA). PSA Testing for the Pretreatment Staging and Posttreatment Management of Prostate Cancer: 2013 Revision of 2009 Best Practice Statement. AUA; 2013.
- Andriole GL, Bostwick DG, Brawley OW, et al. Effect of dutasteride on the risk of prostate cancer. N Engl J Med. 2010;362(13):1192–1202.
