Prostate Volume Calculator

Q: Does a CT angiogram chest-abdomen-pelvis show prostate volume?

Yes. A CT angiogram that covers the chest, abdomen, and pelvis can show the prostate, even though it’s usually ordered for vascular or other reasons. However, CT doesn’t have the same soft-tissue contrast as ultrasound or MRI , so the length, width, and height measurements may be less precise for prostate measurements.

Q: How can I calculate prostate volume?

You can calculate prostate volume using length, width, and height measurements from an ultrasound, CT, or MRI scan. Here’s the general process: Measure length, width, and height in centimeters. Choose a formula : ellipsoid (L × W × H × π/6) or bullet (L × W × H × 5π/24). Multiply the three dimensions by the chosen formula’s constant. The result is given in mL (milliliters), equivalent to cc .

Q: What is a PSA prostate test?

A PSA test checks the level of prostate-specific antigen , a protein made by prostate cells, in your blood. If the PSA is higher than roughly 4.0 ng/mL , it could mean an enlarged prostate, inflammation, or an infection. To get a clearer read, doctors often look at PSA density , which is PSA divided by the prostate’s volume.

Q: What size of prostate is dangerous?

There isn’t a single dangerous size for the prostate. Volumes over about 30 mL are considered enlarged, and around 80 to 100 mL , it’s quite enlarged. Size alone doesn’t tell you the risk. Symptoms, PSA density, and how fast it grows over time matter more .

Creators

Joanna Śmietańska, PhD

Joanna ŚmietańskaPhD, AGH University of Krakow, Cracow, Poland

Website

Research Gate

Joanna Śmietanska-Nowak is an academic teacher at AGH University of Science and Technology in Kraków. Her research interests focus on protein crystallography and modulated systems, though she has previously worked on photocatalysis and energy storage systems, including supercapacitors and Li-ion batteries. She has participated in and led several research projects funded by the Polish National Science Centre. While working at Omni, she primarily developed calculators related to physics, chemistry, and mathematics. In her free time, she enjoys playing board games, cooking, hiking, and brewing beer. See full profile

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Reviewers

Julia Kopczyńska, PhD candidate

Julia KopczyńskaPhD candidate, Polish Academy of Sciences

Research Gate

Julia is a devoted microbiologist who takes a holistic approach to health. She always aims to do her best research and find new solutions to common challenges. As a passionate advocate for a balanced, healthy lifestyle, she offers practical advice grounded in scientific knowledge. A lover of coffee and adventure, Julia enjoys exploring new places, going on scenic walks, and reading insightful books. She has a strong desire to help others lead a balanced, vibrant life by integrating scientific knowledge and personal well-being. See full profile

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and Steven Wooding

Steven Wooding

Steven Wooding is a physicist by training with a degree from the University of Surrey specializing in nuclear physics. He loves data analysis and computer programming. He has worked on exciting projects such as environmentally aware radar, using genetic algorithms to tune radar, and building the UK vaccine queue calculator. Steve is now the Editorial Quality Assurance Coordinator here at Omni Calculator, making sure every calculator meets the standards our users expect. In his spare time, he enjoys cycling, photography, wildlife watching, and long walks. See full profile

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Omni Calculator’s prostate volume calculator is a smart tool to quickly estimate prostate gland volume from three simple ultrasound or MRI measurements: length, width, and height.

This calculation of prostate volume relies on two standard clinical formulas: the ellipsoid model and the bullet model, so you can compare results and choose the one that best fits the gland’s shape. Whether you need to estimate prostate volume for BPH monitoring, PSA density assessment, or general reference, this tool provides a quick estimate.

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace a qualified healthcare professional’s assessment. If any health condition bothers you, consult a physician.

What is prostate gland and how to estimate prostate volume

The prostate is a small, walnut-sized gland below the bladder. It produces fluid that forms part of semen. As men get older, the prostate often grows, and benign prostatic hyperplasia (BPH) is a common cause of prostate enlargement. For this reason, monitoring prostate size can be relevant to urinary health.

To estimate prostate volume, doctors usually measure three dimensions: length, width, and height, using transrectal ultrasound, CT, or MRI, with all values in centimeters.

What is normal prostate volume?

Normal prostate volume is usually around 15 to 30 mL in younger men, and it slowly grows with age as part of getting older. If the volume is higher than that, especially with an elevated PSA (prostate-specific antigen), it could indicate BPH or suggest you should have it checked further. However, there are other possible causes of an elevated PSA. Prostate volume is only an estimate, and small differences in how measurements are taken can affect the result, so consistent measurement is important.

People often compare their results to what’s typical for their age, which is one of the most common reasons people use a prostate gland volume calculator.

💡 You might also be interested in our urine output calculator.

PSA test and normal range

The prostate-specific antigen (PSA) test measures the level of PSA in your blood, typically reported in ng/mL. It’s one of the most common tools doctors use, often alongside imaging, to gauge prostate health. The normal range of the PSA test is generally considered to be below 4.0 ng/mL, but the number shifts with age and prostate size; larger glands naturally tend to produce more PSA.

A result above the usual range does not by itself diagnose cancer. It can also point to BPH, inflammation, or a recent urinary tract issue. That’s why doctors often look at PSA density, which is PSA divided by prostate volume, to get a clearer sense instead of relying on the PSA number alone. For people with advanced prostate cancer, Omni’s prostate survival calculator can help put the prognosis into context.

💡 If your PSA level rises across repeated tests, doctors may track PSA doubling time. A faster rise can signal more active disease, while a slow, steady increase is often just age-related prostate growth.

Prostate volume formula

The most widely used prostate volume formula treats the gland as a prolate ellipsoid:

V = L \times W \times H \times π/6

where:

$L$ — Length;
$W$ — Width; and
$H$ — Height of the prostate.

All measurements are in centimeters, giving volume in mL (milliliters).

An alternative is the bullet formula, which models the prostate as a cylinder topped with a half-ellipsoid, which is often a better fit for smaller glands:

V = L \times W \times H \times 5π/24

Both formulas are widely used in clinical practice. Our prostate volume calculator can run them side by side, allowing you to compare the results. When the gland is under 55 mL, the bullet formula tends to match the gland’s shape a bit better in some patients. The ellipsoid formula is still the standard reference for general use.

Once you have a prostate volume estimate, you can also calculate PSA density. It’s simply your PSA level divided by prostate volume:

\mathrm{PSAD} = \frac{\mathrm{PSA}}{V}

If PSA is measured in ng/mL and prostate volume in mL, PSA density is expressed in ng/mL².

How to use prostate volume calculator

Using our prostate gland volume calculator is straightforward:

First, choose the calculation model you wish to use or select to compare the two models. The bullet model may better estimate the volume of prostates under 55 mL, while the ellipsoid model is the standard reference in most cases.
Enter your measurements in centimeters to calculate prostate volume instantly.
Review the prostate volume results.
Optionally, open the Calculate PSA density section of the calculator and enter your PSA level (ng/mL) to calculate PSA density; it may help clinicians interpret PSA results alongside prostate volume and other clinical information.

Our prostate gland volume calculator is designed for radiologists, urologists, and patients seeking a quick, reliable estimate of prostate volume without manual calculation.

FAQs

Does a CT angiogram chest-abdomen-pelvis show prostate volume?

Yes. A CT angiogram that covers the chest, abdomen, and pelvis can show the prostate, even though it’s usually ordered for vascular or other reasons. However, CT doesn’t have the same soft-tissue contrast as ultrasound or MRI, so the length, width, and height measurements may be less precise for prostate measurements.

How can I calculate prostate volume?

You can calculate prostate volume using length, width, and height measurements from an ultrasound, CT, or MRI scan. Here’s the general process:

Measure length, width, and height in centimeters.
Choose a formula: ellipsoid (L × W × H × π/6) or bullet (L × W × H × 5π/24).
Multiply the three dimensions by the chosen formula’s constant.
The result is given in mL (milliliters), equivalent to cc.

What is a PSA prostate test?

A PSA test checks the level of prostate-specific antigen, a protein made by prostate cells, in your blood. If the PSA is higher than roughly 4.0 ng/mL, it could mean an enlarged prostate, inflammation, or an infection. To get a clearer read, doctors often look at PSA density, which is PSA divided by the prostate’s volume.

What size of prostate is dangerous?

There isn’t a single dangerous size for the prostate. Volumes over about 30 mL are considered enlarged, and around 80 to 100 mL, it’s quite enlarged. Size alone doesn’t tell you the risk. Symptoms, PSA density, and how fast it grows over time matter more.