It's unknown exactly how old Jesus was at the time of his death, but it's widely believed that he was 33. Jesus was crucified on the cross under the direction of Pontius Pilate, who was governor of Judea at the time.
For Jesus to be consecrated as a priest, he would have had to be at least 30 years old, which means that was the earliest age he would have been able to begin his ministry. It's believed that Jesus spent at least one year, and as many as three years, preaching and gathering followers. This leads to the estimation that Jesus was 33 at the time of his death.