en_tn/ezk/43/13.md

a cubit ... two cubits ... four cubits

Each "long cubit" was about 54 centimeters. You may choose not to include this information if you give modern measurements instead of "cubits" as the UDB does. See how you translated this in Ezekiel 40:5. AT: "about 54 centimeters ... about 1.1 meters ... about 2.2 meters" (See: rc://en/ta/man/translate/translate-bdistance)

The border around its surrounding edge

"The border going around its edge"

one span

A span was 23 centimeters. You may choose not to include this information if you give modern measurements instead of "cubits" as the UDB does. AT: "about 23 centimeters" (See: rc://en/ta/man/translate/translate-bdistance)

This will be the base of the altar

"These will be the measurements of the base of the altar"

the base of the altar

"the bottom supporting the altar" or "the foundation of the altar"