“Then he made an altar of bronze.” Interestingly, this bronze altar that Solomon made to replace the smaller one made by Moses is not described in 1 Kings 7, when the articles of the Temple are being discussed, but it is mentioned in 1 Kings 8:22 when Solomon dedicates the Temple.
“20 cubits.” The dimensions of this altar are not mentioned in the book of Kings. This huge altar had the same dimensions as the Holy of Holies (2 Chron. 3:8).
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.