Prostate-Specific Antigen (PSA), Free-to-Total Ratio
Below is a plain-language overview of the prostate-specific antigen (psa), free-to-total ratio. The free-to-total PSA ratio is a follow-up blood test that compares two forms of prostate-specific antigen (PSA), a protein made by the prostate gland. It is usually ordered when a total PSA result is mildly elevated, to help a clinician decide whether further prostate evaluation is needed. It is not a cancer diagnosis test by itself.
- Sample type
- blood
- Category
- Cancer Screening
- Turnaround
- 1-3 business days
- Price
- $178
- Referral
- Not required
The free-to-total PSA ratio is a follow-up blood test that compares two forms of prostate-specific antigen (PSA), a protein made by the prostate gland. It is usually ordered when a total PSA result is mildly elevated, to help a clinician decide whether further prostate evaluation is needed. It is not a cancer diagnosis test by itself.
What it measures
- Total PSA — The overall amount of PSA in the blood, both bound and unbound.
- Free PSA — The portion of PSA that is not attached to other proteins.
- Free-to-total PSA ratio — Free PSA divided by total PSA, often expressed as a percentage. A lower percentage can sometimes point toward a higher chance of prostate cancer, but it is only one piece of information.
Who it is for
This test is typically ordered by a primary care clinician or urologist for men who have a mildly elevated total PSA and no clear explanation, such as a recent prostate infection or procedure.
Preparation
No fasting is required. Tell your clinician about any recent prostate exam, biopsy, urinary infection, or ejaculation, because these can temporarily raise PSA levels.
Results and what they mean
Results are reported as a percentage along with the total and free PSA values. Your clinician interprets the ratio together with your age, prostate exam findings, and health history. This information is general and not medical advice; only your clinician can explain what your results mean for you.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the prostate-specific antigen (psa), free-to-total ratio is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
Does a low free-to-total PSA ratio mean I have cancer?
No. A low ratio may raise concern, but it does not diagnose cancer. Many benign prostate conditions can also affect the ratio.
Do I need to fast for this test?
No. Fasting is not required for PSA testing.
Can I have sex before the test?
Ejaculation can briefly raise PSA. Ask your clinician how long to avoid it before your blood draw.
How long do results take?
Most results are available within 1 to 3 business days.