What is the normal volume of testicles in milliliters (mL)?

Normal Testicular Volume in Adult Males

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, 2

Reference Values by Measurement Method

Different measurement techniques yield slightly different normal ranges:

• Ultrasonography: 15-25 ml (most accurate method)

  • Mean volume: 17 ± 8 ml 3
  • Calculation formula: length × width × height × 0.71 2

• Prader Orchidometer:

  • Mean volume: 16 ± 7 ml 3
  • Normal adult range: >14 ml in Japanese men, >17 ml in American men 4

• Ruler measurement:

  • Mean volume: 15 ± 8 ml 3
  • Simple and cost-effective clinical method 3

Clinical Significance of Testicular Volume

Fertility Implications

• Total testicular volume (both testes combined) correlates significantly with sperm parameters and hormonal profiles 2
• Critical thresholds for normal testicular function:
  • By ultrasonography: ≥20 ml total volume (both testes)
  • By Prader orchidometry: ≥30-35 ml total volume (both testes) 2

Risk Assessment

• Testicular volumes <12 ml are considered atrophic 1
• Men with testicular volumes <12 ml and age >30 years have a 34% risk of intratubular germ cell neoplasia (TIN) in the contralateral testis 1
• Small testicular volume is associated with:
  • Hypogonadism
  • Infertility
  • Higher risk of testicular pathology 5

Population Variations

Testicular volume may vary by ethnicity and population:

• Vietnamese men: mean testicular volume of 13.64 ± 3.44 ml 5
  • Left testis: 13.94 ± 3.72 ml
  • Right testis: 13.34 ± 3.61 ml
• In many populations, the left testis is typically slightly smaller than the right 5, 6

Correlations with Hormonal Parameters

• Testicular volume negatively correlates with FSH and LH levels (Rho = -0.33 and -0.16, respectively) 5
• Positive correlation with testosterone levels 5
• Testicular volume is generally independent of age in adult males 5

Clinical Pearls

• For routine clinical assessment, a simple ruler measurement is often adequate and cost-effective 3
• Ultrasonography provides the most accurate measurement and should be used when precise volume determination is required 1
• When evaluating male infertility, testicular volume should be considered alongside hormonal parameters and semen analysis 7
• Testicular volumes <12 ml warrant further evaluation, especially in men >30 years of age 1