Example 1 — Typical gland
\(L=4.8\ \mathrm{cm},\ W=3.9\ \mathrm{cm},\ H=3.7\ \mathrm{cm}\). \(V \approx 0.523 \times 4.8 \times 3.9 \times 3.7 \approx 36.2\ \mathrm{mL}\).
Prostate Volume Calculator
Prostate Volume Calculator estimates gland volume from imaging dimensions, shows formulas, examples, and PSA density; educational, unit-consistent outputs, with tips.
Mid-sagittal cranio-caudal dimension (centimeters).
Transverse right-left diameter (centimeters).
Anterior-posterior diameter (centimeters).
Serum PSA used to compute PSA density: PSAD = PSA ÷ volume.
Equation Preview
V (mL) = L × W × H × π/6 ≈ 0.523 × L × W × H
PSA density (PSAD) = PSA (ng/mL) ÷ V (mL)
Helping Notes
- Use centimeters for L, W, H. Volume returns as milliliters (mL), equal to cubic centimeters (cc).
- PSA density (ng/mL per mL) is a simple ratio: serum PSA divided by gland volume.
- If any dimension is 0, volume and PSAD can’t be computed—enter realistic measured values.
Results
Ellipsoid Volume
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PSA & PSA Density
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Equation with Numbers
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Input Recap
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What is a Prostate Volume Calculator?
A Prostate Volume Calculator is a simple tool that converts three orthogonal measurements of the prostate—length, width, and height—into an estimated volume in milliliters (mL, equivalent to cubic centimeters, cc). Clinically, volume estimates support reporting, therapy planning, and derived indices such as PSA density. The calculator implements the widely used ellipsoid model, which approximates the prostate as a prolate ellipsoid. When measurements are taken consistently (usually on TRUS or MRI), this model provides a quick, reproducible estimate suitable for documentation and longitudinal comparison. It is an educational aid and not a diagnostic device.
About the Prostate Volume Calculator
The ellipsoid approach multiplies the three dimensions and scales by \( \pi/6 \approx 0.523 \). Typical inputs are in centimeters; because \(1\ \mathrm{mL}=1\ \mathrm{cm^3}\), the numerical result directly reads in milliliters. The tool also supports basic unit handling (e.g., if measurements are collected in millimeters, divide by 10 to convert to centimeters before calculation). For contexts where PSA density is useful, the calculator can divide a provided PSA value by the computed volume to produce an illustrative density. Real-world accuracy depends on image plane selection, measurement technique (outer-to-outer vs. inner), and anatomic variations; when available, modality-specific methods (planimetry or segmentation) may improve precision.
How to Use this Prostate Volume Calculator
- Measure Length (L) apex-to-base on mid-sagittal, Width (W) maximal transverse on axial, and Height (H) anteroposterior on the best plane; record in centimeters.
- Confirm units. If in millimeters, convert: \( \mathrm{cm} = \mathrm{mm}/10 \).
- Enter \(L, W, H\). (Optional) Enter PSA if you want an illustrative PSA density.
- Calculate to see volume in \( \mathrm{cm^3}=\mathrm{mL} \) and, if provided, PSA density.
- Document technique and remain consistent across follow-up measurements for better trend comparisons.
Core Formulas (LaTeX)
Ellipsoid volume (prolate ellipsoid model): \[ V = \frac{\pi}{6}\,L\,W\,H \;\approx\; 0.523\,L\,W\,H \quad (\text{with } L,W,H \text{ in cm and } V \text{ in mL}). \]
Unit relations: \[ 1\ \mathrm{mL} = 1\ \mathrm{cm^3}, \qquad \mathrm{cm} = \frac{\mathrm{mm}}{10}. \]
Illustrative PSA density (optional): \[ \mathrm{PSAD} = \frac{\mathrm{PSA\ (ng/mL)}}{V\ (\mathrm{mL})} \quad \text{(often expressed as ng/mL per mL, i.e., ng/mL/cc)}. \]
Examples (Illustrative)
Example 2 — Enlarged gland with PSA density
\(L=5.6,\ W=4.9,\ H=5.2\ \mathrm{cm}\Rightarrow V \approx 0.523 \times 5.6 \times 4.9 \times 5.2 \approx 74.6\ \mathrm{mL}\). PSA \(=6.2\ \mathrm{ng/mL}\Rightarrow \mathrm{PSAD}=6.2/74.6\approx0.083\ \mathrm{ng/mL/cc}\).
Example 3 — Small gland (mm to cm conversion)
Measurements \(= 38\times32\times30\ \mathrm{mm} \Rightarrow 3.8, 3.2, 3.0\ \mathrm{cm}\). \(V \approx 0.523 \times 3.8 \times 3.2 \times 3.0 \approx 19.1\ \mathrm{mL}\).
FAQs
Which dimensions correspond to length, width, and height?
Length: apex-to-base (sagittal). Width: maximal transverse (axial). Height: anteroposterior (best plane available).
Should I enter measurements in mm or cm?
Use centimeters. Convert mm to cm by dividing by 10; the volume output will be in mL (cc).
Why use the ellipsoid model?
It’s fast and reproducible across modalities; while approximate, it is widely used for reporting and follow-up.
How accurate is the estimate?
Accuracy depends on measurement technique and anatomy. Planimetry/segmentation may be more precise when available.
What is PSA density?
PSA divided by prostate volume; shown here for illustration only. It is not a diagnostic on its own.
Can I compare results over time?
Yes—use the same modality and measurement planes each time for more reliable trends.
Is this calculator a medical diagnosis tool?
No. It is educational and supports documentation. Clinical decisions require professional evaluation and imaging reports.