What is the normal range/average testicular volume as measured by ultrasound? is it at all different from prader orchidometer or caliper measurements?

TESTES: They are all estimates and there are many factors that go into the estimate. Adult males ave testis length vs vol. Estimate.

Range & methods vary: Population based studies have found adult 95% of testes to be 4-8cm in length, & 18-25ml in volume. Ultrasound (us) & orchidometry studies estimate testis volume based on calculations & are subject to error. The best study comparing methods was performed in japan in 2007 and showed that us was significantly more accurate (r=0.91) than prader orchidometry (r=0.80) when l x w x h x 0.71 was used.

Average should be 20: Average should be 20-25cc most urologist if concerned will get us to determine actual size.