The Bible does not say how old Jesus was when He died. Further, the Bible does not give the date of Jesus’ birth or the date His death. This makes determining Jesus’ precise age when He died impossible. As a background, please read our articles on “What year was Jesus Christ born?” and “In what year did Jesus die?”
By tracing the history recorded in the New Testament, especially the Gospel of Luke, and comparing it with Roman history, we conclude that Jesus was born between 6 and 4 BC, near to the time of King Herod’s death. In estimating the age of Jesus, we can split the difference and say He was born in 5 BC.
Next, we need to determine the date of the start of Jesus’ ministry. Luke 3:1 says that John the Baptist started preaching in the fifteenth year of Tiberius’s reign, which would be c. AD 28 or 29. Jesus was probably baptized and began His ministry sometime in AD 29 when He was about 33 years old.
And then we determine the date of the end of Jesus’ ministry. Based on the number of Passover feasts Jesus observed during His public ministry—three of which are mentioned in Scripture—He ministered for approximately three and a half years. That would place the end of Jesus’ ministry in AD 33.
So, it is likely that Jesus was crucified in AD 33. (There is another theory that calculates the beginning of Jesus’ ministry differently, arriving at a crucifixion date of AD 30. Both these dates fit the historical data we have that Pontius Pilate governed Judea from AD 26–36, and Caiaphas the high priest was also in office until AD 36.)
Doing the math:
5 BC to 1 BC = 4 years,
and AD 1 to AD 33 = 33 years,
for a total of 37 years.
Jesus was thus in His 30s when He was crucified. Depending on the exact date of His birth and the year He commenced His public ministry, Jesus was somewhere between 33 and 39 years old when He died.
So, while it is impossible to be precise or dogmatic, the answer to the question “How old was Jesus when He died?” is “approximately 36 years old.”