What is the normal volume of a testicle in milliliters (ml)?

Normal Testicular Volume in Adult Males

The normal testicular volume in adult males ranges from 15 to 25 ml, with volumes below 12 ml considered atrophic and potentially associated with higher risk of testicular pathology. 1

Testicular Volume Assessment

Normal Range and Clinical Significance

• Adult male testicular volume typically falls between 15-25 ml 1
• Volumes below 12 ml are considered atrophic and warrant further evaluation 1
• Testicular volumes <12 ml in men >30 years are associated with a 34% risk of intratubular germ cell neoplasia (TIN) in the contralateral testis 2, 1
• Mean testicular volume in healthy subjects has been reported as 13.64 ± 3.44 ml in a large Vietnamese study 3
  • Left testis: 13.94 ± 3.72 ml
  • Right testis: 13.34 ± 3.61 ml (statistically significant difference, p<0.001)

Measurement Methods

1. Ultrasound (Gold Standard)

   • Most accurate method for precise volume determination 1
   • Recommended formula: Length × Width × Height × 0.52 (prolate ellipsoid formula) 4
   • Alternative formulas:
     • Hansen formula: Length × Width² × 0.52 4
     • Lambert equation: Length × Width × Height × 0.71 4
   • Particularly important in cases with:
     • Large hydrocele
     • Inguinal testis
     • Epididymal enlargement/fibrosis
     • Thickened scrotal skin
     • Small testes 1

2. Prader Orchidometer

   • Recommended by European Association of Urology for routine clinical practice 1
   • Good surrogate for ultrasound measurements
   • Cost-effective and easier to perform 1
   • May slightly overestimate volume compared to ultrasound 5

3. Ruler Measurement

   • Simple, available, and low-cost option 5
   • Formula: Length × Width × Height × (π/6) 6
   • Correlates significantly with other methods 5

Clinical Implications

Risk Assessment

• Testicular volumes <12 ml are associated with:
  • Higher risk of testicular cancer 1
  • Potential infertility issues 1
  • Possible hormonal abnormalities 7

Correlation with Hormonal Profiles

• Testicular volume negatively correlates with:
  • Luteinizing hormone (LH) (Rho = -0.16) 3
  • Follicle-stimulating hormone (FSH) (Rho = -0.33) 3
• Positively correlates with testosterone levels 3

Age-Related Considerations

• Testicular volume increases significantly during puberty 6
• By age 13, testicular volume typically exceeds 3 ml 6
• In adults, testicular volume appears to be independent of age 3

Common Pitfalls and Caveats

• Different measurement methods may yield slightly different results; consistency in method is important for follow-up
• Ultrasound measurements using different formulas can vary significantly; the prolate ellipsoid formula (L×W×H×0.52) appears most accurate for smaller testes 4
• When evaluating for pathology, consider both absolute volume and asymmetry between testes
• Men with testicular volumes <12 ml and age >30 years should be considered for testicular biopsy due to increased risk of TIN 2
• Testicular architecture and structure should be assessed alongside volume, as non-homogeneous patterns may indicate testicular dysgenesis 1