Prostate Volume to Weight Conversion

Your imaging report shows prostate volume in cubic centimeters (cc), but your surgeon talks about weight in grams. How do these relate? The conversion is straightforward—but understanding the science behind it helps you communicate with your medical team.

The Basic Conversion

Prostate tissue has a specific density slightly greater than water:

This means a 50cc prostate weighs approximately 52.5 grams. The relationship is nearly 1:1, with the 5% difference accounting for tissue density.

Convert your volume automatically with our Prostate Weight Calculator.

Where Does 1.05 Come From?

The density factor of 1.05 g/cc (or 1.05 g/mL) is derived from tissue analysis studies:

• Water has density of 1.0 g/cc
• Prostatic tissue is slightly denser due to:
  • Glandular tissue components
  • Smooth muscle fibers
  • Fibrous stroma
• Multiple studies confirm the 1.05 figure

Research Validation

Studies comparing imaging-estimated volume to pathological weight (after surgical removal) consistently show:

• Correlation coefficients of 0.90-0.95
• Mean density of 1.04-1.06 g/cc
• 1.05 accepted as standard conversion factor

Quick Conversion Table

Why Surgeons Use Weight

While imaging provides volume, surgeons often think in weight because:

• Resection rates: TURP removes ~1 gram/minute
• Blood loss: Estimated per gram of tissue
• Pathology: Lab weighs resected tissue, enabling comparison
• Historical data: Surgical literature uses weight

When Volume vs. Weight Is Reported

Volume (cc) Typically From:

• Transrectal ultrasound (TRUS)
• Abdominal ultrasound
• MRI reports
• CT scans

Weight (g) Typically From:

• Surgical planning discussions
• Pathology reports (post-surgery)
• Research literature

Accuracy Considerations

Sources of Variation

• Individual density: Ranges from ~1.02 to 1.08 g/cc
• Tissue composition: More fibrous tissue = slightly denser
• Volume measurement accuracy: Imaging error ± 10-15%

Clinical Impact

These variations rarely matter clinically. A 50cc prostate might actually weigh 51-54g instead of exactly 52.5g—not enough to change treatment decisions.

Practical Application

1. Get your volume from imaging (use our Volume Calculator if you have dimensions)
2. Convert to weight with our Weight Calculator
3. Discuss with your surgeon using the terminology they prefer

Key Takeaways

Convert your measurement with our free Prostate Weight Calculator.