Then he made an altar of bronze, twenty cubits its length and twenty cubits its breadth and ten cubits its height. Bible

“twenty cubits.” Most scholars think this is the standard cubit of 18 inches, which would make the bronze altar 30 feet by 30 feet (9 x 9 meters), and 15 feet (4.6 m) high. Although it was said to be made of bronze, it is unclear how much of it was bronze. The priests ministered in bare feet, so it seems clear that the top of it that had the perpetual fire could not have been bronze or the priests could not have walked there. Similarly, the ramp up to the top would not have been bronze or in the summer the Judean sun would have made the ramp too hot to walk on.

Commentary for: 2 Chronicles 4:1