How big was the stone in front of the tomb of Jesus?

The stone would certainly have been large enough to block an entrace through which at least two men could carry a body. It was so large that, in Mark's Gospel, the three women realised that together they could not roll it away from the entrance (Mark 16:3-4): "And they said among themselves, Who shall roll us away the stone from the door of the sepulchre? And when they looked, they saw that the stone was rolled away: for it was very great."

However, there is an anomaly in the gospel story. Round stones that could be rolled away were commonly used in Judea after 70 CE, when the gospels were being written. However, in 30 or 33 CE, the time of the crucifixion, squarish stones with corners were invariably used. The stone should have been described as both large and square, to deter grave robbers, and there should have been no assumption in the gospels of the stone being rolled away (cf Matthew 28: "And, behold, there was a great earthquake: for the angel of the Lord descended from heaven, and came and rolled back the stone from the door, and sat upon it.").