| | Conditions Treatments | Aneurysm How large is the appendix? The size of the appendix can vary from person to person, but on average, it is about 2-4 inches (5-10 cm) long and 0.4 inches (1 cm) in diameter. Aneurysm - Related Articles How does cigarette smoking impact the risk of testicular cancer? Respiratory Protection Training How to Quickly Lose Weight In Your Arms How to Treat Bursitis in the Elbow The Dangers of Mixing Fat Burners & Enhancers How to Make a Child Gain Weight Prognosis of Glioblastoma