# What is my PSA density?

Divides the serum PSA by the prostate volume to give the PSA density (PSAD) in ng/mL per mL, and compares it with the published 0.15 cut-off.

- Page: https://www.acalculator.org/health/psa-density-calculator
- JSON spec: https://www.acalculator.org/health/psa-density-calculator.json
- Version: 0a5570cff9db

## Default answer

Example with the default inputs (PSA (ng/mL) 6, Prostate volume (mL) 40): The PSA density is 0.15 ng/mL per mL: 0.15 or more.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| psa | PSA (ng/mL) | Serum prostate-specific antigen, 0.01 to 1,000 ng/mL. |
| volume | Prostate volume (mL) | Prostate volume from ultrasound or MRI, 5 to 500 mL (1 mL = 1 cc). |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| psad | PSA density (ng/mL per mL) | PSA ÷ prostate volume, to 2 decimals. |
| cutoff | Against the 0.15 cut-off | Whether the PSA density shown is under 0.15 or 0.15 or more (Bazinet 1994). |

## Method

PSA density = serum PSA (ng/mL) ÷ prostate volume (mL), to 2 decimals. Cut-off 0.15 (Bazinet 1994).

## Assumptions

- The prostate volume comes from transrectal ultrasound or MRI, in mL (cc).
- The density is rounded once to 2 decimals, halves up, and the shown value is compared with 0.15.

## Worked examples

1. psa = 6, volume = 40 gives psad = 0.15, cutoff = 0.15 or more. Source: Benson 1992: 6 ÷ 40 = 0.15, at the 0.15 cut-off (Bazinet 1994).
2. psa = 8, volume = 80 gives psad = 0.1, cutoff = Under 0.15.
3. psa = 5.2, volume = 35 gives psad = 0.15, cutoff = 0.15 or more.
4. psa = 4.9, volume = 35 gives psad = 0.14, cutoff = Under 0.15.

## FAQ

### How is PSA density calculated?

Divide the serum PSA in ng/mL by the prostate volume in mL (cc). A PSA of 6 ng/mL with a 40 mL prostate gives 6 ÷ 40 = 0.15.

### What is a normal PSA density?

There is no single normal value. Bazinet et al. (1994) found 0.15 the best cut-off in men with a PSA of 4.1 to 10 ng/mL and a normal rectal exam and ultrasound; below it, few cancers were missed.

### Why divide PSA by prostate size?

A larger prostate makes more PSA even without cancer. Benson et al. (1992) proposed PSA density to help tell benign enlargement (BPH) from cancer: in their study the mean density was 0.044 with BPH and 0.581 with cancer.

### Where do I find my prostate volume?

It is in a transrectal ultrasound or prostate MRI report, in mL or cc (the same unit). The prostate volume calculator works it out from the three measured lengths.

### Does a PSA density over 0.15 mean cancer?

No. It is one risk marker. Many men with a density over 0.15 do not have cancer, and some with a lower density do. A urologist reads it with the PSA, the exam, and imaging.

## Sources

- Benson MC, Whang IS, Pantuck A, et al. Prostate specific antigen density: a means of distinguishing benign prostatic hypertrophy and prostate cancer. J Urol. 1992;147(3 Pt 2):815-816. https://doi.org/10.1016/s0022-5347(17)37393-7 (retrieved 2026-10-05)
- Bazinet M, Meshref AW, Trudel C, et al. Prospective evaluation of prostate-specific antigen density and systematic biopsies for early detection of prostatic carcinoma. Urology. 1994;43(1):44-51. https://doi.org/10.1016/s0090-4295(94)80260-2 (retrieved 2026-10-05)