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Free PSA Unit Converter
Free Prostate-Specific Antigen (Free PSA) is the unbound form of PSA circulating in the blood. While Total PSA measures both bound and unbound forms, measuring Free PSA is particularly useful when Total PSA levels are in the “gray zone” (4.0 – 10.0 ng/mL).
The percentage of Free PSA (%fPSA) helps distinguish between benign prostatic hyperplasia (BPH) and prostate cancer. A lower percentage of Free PSA is associated with a higher risk of malignancy. This converter facilitates switching between standard mass units used in laboratory reports.
Common Mass Units
StandardNanograms per milliliter (Numerically equivalent to μg/L).
Other Equivalents
Clinical Context (Free/Total Ratio)
Interpretation of % Free PSA:
• > 25%: Lower risk of cancer (~8% probability). Likely BPH.
• < 10%: Higher risk of cancer (~56% probability). Biopsy is often recommended.
Conversion Logic:
1 ng/mL = 1 μg/L.
1 ng/mL = 100 ng/dL.
Clinical References
How to Use This Converter
Follow these steps to normalize Free PSA values.
Enter Values
Input your laboratory results into the corresponding unit field (e.g., ng/mL).
Automatic Conversion
The calculator instantly updates all other fields. For Free PSA, ng/mL and μg/L will always show the same value.
Reset
Use the Clear button to reset all fields.
Frequently Asked Questions
Yes. This tool converts the units for the Free portion of PSA. Total PSA measures both free and bound forms.
No, this tool only converts units. To calculate the ratio, divide Free PSA by Total PSA (ensuring both are in the same unit).