Interpret My PSA – Prostate-Specific Antigen (PSA) Interpreter

Understand your PSA result

A PSA result is one piece of information about prostate health. This tool helps you read that number alongside previous results and any related measurements you already have. It shows what can be calculated, explains when a comparison is available, and helps you prepare questions for your clinician.

PSA can rise for reasons other than cancer, and a lower value does not rule cancer out. Your history, medicines and the reason for testing matter. Results after a prostate cancer diagnosis or treatment need an individual interpretation from your care team. NCI’s guide to the PSA test explains these distinctions.

How to use the PSA Interpreter

1. Enter Total PSA in ng/mL. Age is optional and uses completed years, not an age band. Answer the questions about why you were tested and anything that might affect PSA. Leave “Not sure” selected when you do not know.
2. Choose Review my results. You can reach your basic explanation without opening the optional sections.
3. If you have them, add previous PSA and the interval in months, prostate volume, paired free PSA, or a laboratory-reported PHI or 4Kscore. Enter free PSA as a concentration in ng/mL, not as a percentage. Then choose Update my results.
4. Read each explanation and its limitations. Editing an entry clears the old result until you review again. Reset clears the entries and returns the context questions to “Not sure”.

Keep your original reports and test dates handy. Blank means unavailable; zero means the report actually says zero. If a result includes a qualifier such as “<0.1”, keep it intact. The tool cannot interpret that as an exact number and will explain the limitation. Do not remove the qualifier or substitute zero.

What the results can tell you

Calculated measurements

PSA density relates total PSA to prostate volume. Percent-free PSA is the proportion of total PSA measured as free PSA, using compatible paired measurements. The tool also shows your previous and current PSA with the interval between them; an annualized change is available in the explanation. These calculations describe the entries you supply. They do not establish why a value changed or diagnose cancer. PSA change alone should not determine whether you need further tests. [1] [2] [4]

Comparisons that depend on context

When the required answers support it, total PSA is compared with a historical age reference. This is a comparison with an older study, not a personal cancer probability or a universal “normal” limit. Its population and laboratory method may differ from yours. [3]

The density comparison uses the selected MRI result and other answers. Different MRI findings have different clinical contexts; density alone cannot establish clinical suspicion or decide whether a biopsy is needed. The tool explains when information is missing and when your selected circumstances fall outside its comparison rules. It cannot replace assessment of all the findings by a clinician. [2]

Values are rounded for display, while comparisons use unrounded calculations. Near a reference, a displayed value may look equal even though the underlying calculation is slightly below or above it. The result explains this when it occurs. There is no combined risk score or low-to-high risk meter.

Scores copied from a laboratory report

Prostate Health Index (PHI) and 4Kscore are shown as reported entries. This calculator does not calculate PHI from its components, authenticate a laboratory result or confirm that a test applies to you. It does not assign a new probability or category. A PHI score is not a percentage; the reported 4Kscore concerns the likelihood of high-grade cancer on biopsy, not lifetime cancer risk. Discuss the original report and its test-specific limitations with your clinician. [5] [6]

Use the explanation for your next conversation

Bring the full laboratory report, previous test dates and your medication list. Ask whether the measurements are comparable, whether anything might have affected the result, and what follow-up fits your circumstances. A newly elevated PSA may need confirmation before further testing; the timing is a clinical decision. Do not adjust a result or stop medicine yourself. [1] NCI PSA information.

If an entry is outside the calculator’s supported range, that does not mean the laboratory result is impossible. Keep the value as reported and discuss it with your clinician. This educational tool cannot diagnose or rule out cancer and has not been independently clinically validated.

For more background, read Prostate-Specific Antigen (PSA): What You Need to Know.

Privacy

The calculator’s own code processes entries in your browser without sending or saving them. The surrounding website and other software may still access entries or make network requests. Site analytics have been observed, and health-value transmission and retention have not been fully verified. This is not a guarantee that all information stays on your device. Do not enter names or other identifying details. See the calculator’s privacy help and the site privacy policy for more context.

References

1. AUA/SUO. Early Detection of Prostate Cancer, 2023 guideline amended 2026. Statements 3 and 9; discussion of MRI, density and biomarkers. Screening and suspected-cancer guidance, not treatment follow-up advice.
2. EAU Guidelines on Prostate Cancer, 2026: Diagnostic Evaluation. Sections 5.2.2–5.2.3 and 5.5.8.
3. Oesterling et al. JAMA, 1993. Historical age-specific PSA references.
4. Catalona et al. JAMA, 1998. Percent-free PSA in a defined study population. Its cutoff is not applied here.
5. FDA original PHI labeling, 2012 and Beckman Coulter IFU A80984 N, 2020. These versioned documents describe assay-specific use; they do not establish eligibility for an entry copied into this tool.
6. 4Kscore package insert, version 4, March 2026. Intended use, reported scale and limitations.