Average Testicular Volume for a 30-Year-Old Male
The average testicular volume for a healthy 30-year-old male is approximately 13-14 mL per testis (26-28 mL total for both testes) when measured by ultrasound, with volumes of 15-18 mL per testis considered optimal for normal spermatogenesis and fertility. 1, 2
Normal Reference Values
Ultrasound measurements in healthy Vietnamese men showed a mean testicular volume of 13.64 ± 3.44 mL per testis (left: 13.94 mL; right: 13.34 mL), which provides population-based reference data for Asian men around age 30. 2
The clinical threshold of 12 mL per testis represents the lower limit of normal, below which testes are considered atrophic and associated with impaired spermatogenesis. 1, 3
Volumes of 15-18 mL per testis are associated with normal spermatogenesis and adequate fertility potential according to reproductive medicine guidelines. 1
Measurement Method Considerations
Prader orchidometer measurements systematically overestimate testicular volume compared to ultrasound—a 15 mL orchidometer reading corresponds to approximately 10-12 mL by ultrasound. 1, 4
Ultrasound is more accurate than orchidometry for precise volume assessment, particularly for smaller testes, though orchidometry remains cost-effective for routine clinical screening. 1, 5
The Lambert formula (Length × Width × Height × 0.71) provides the most accurate ultrasound-based volume calculation when compared to gold-standard water displacement methods. 5
Clinical Significance of Volume Thresholds
Volumes below 12 mL per testis are definitively considered atrophic and warrant investigation, as they correlate with impaired spermatogenesis, elevated FSH, and increased risk of intratubular germ cell neoplasia. 1, 3
Total testicular volume below 20 mL (both testes combined) by ultrasound correlates with oligozoospermia and subnormal total sperm counts in infertility evaluations. 4
Testicular volume correlates negatively with FSH and LH (indicating compensatory pituitary response to testicular dysfunction) and positively with testosterone levels. 2
Important Clinical Caveats
Age does not significantly affect testicular volume in healthy adult men, so the reference values apply across the adult age spectrum until advanced age. 2
A size discrepancy greater than 2 mL or 20% between testes warrants ultrasound evaluation to exclude pathology, regardless of absolute volume. 1
Testicular volume alone cannot definitively predict fertility status—even normal-sized testes require semen analysis when infertility is a concern. 1
Measurement technique matters critically: improper caliper placement during ultrasound can lead to severely inaccurate volume calculations, so measurements should use high-frequency probes (>10 MHz) with standardized three-dimensional assessment. 1