Francis is 86. He was 76 when elected. The mode age of Popes when elected is between 61-70 (37 out of 103 elected whose exact age is known), with 51-60 right behind (24). 21 were older than 70 (like Francis).
Francis and Benedict are two of the oldest popes at the time of election. Benedict was the 5th oldest, and Francis was in the top 10. There's been a pattern over the past century to elect an older pope after a longer serving pope. Thus, Benedict and Francis were elected after JPII, who served 26 years. Pius XII was 63 when elected and served 19 years, and was succeeded by John XXIII (5 years, one month short of 77 at the time elected). Paul VI was 65 when elected and 80 when he passed. JP I passed 1 month after his election, so JP II at 58 was the youngest at the time of election since 1846.