GOD'S WORD® Translation
It was square, 21 feet wide and 21 feet long.

American Standard Version
And the altar hearth shall be twelve cubits long by twelve broad, square in the four sides thereof.

Berean Study Bible
The altar hearth shall be square at its four corners, twelve cubits long and twelve cubits wide.

Douay-Rheims Bible
And the Ariel was twelve cubits long, and twelve cubits broad, foursquare, with equal sides.

English Revised Version
And the altar hearth shall be twelve cubits long by twelve broad, square in the four sides thereof.

King James Bible
And the altar shall be twelve cubits long, twelve broad, square in the four squares thereof.

World English Bible
The altar hearth shall be twelve [cubits] long by twelve broad, square in the four sides of it.

Young's Literal Translation
And the altar is twelve long by twelve broad, square in its four squares.

Ezekiel 43:16 Additional Translations ...