register, written in Egyptian hieroglyphs, has suffered the most damage. Only the last 14 lines of the hieroglyphic text remain visible; all are broken on the right side, and 12 of them are also damaged on the left. Below it, the middle register of demotic text has survived best; it has 32 lines, of which the first 14 are slightly damaged on the right side. The bottom register of Greek text contains 54 lines, of which the first 27 survive in full; the rest are increasingly fragmentary due to a diagonal break at the bottom right of the stone.

The full length of the hieroglyphic text and the total size of the original stele, of which the Rosetta Stone is a fragment, can be estimated based on comparable steles that have survived, including other copies of the same order. The slightly earlier decree of Canopus, erected in 238 BC during the reign of Ptolemy III, is 2190 mm and abbr=on 820 wide, and contains 36 lines of hieroglyphic text, 73 of demotic text, and 74 of Greek. The texts are of similar length. From such comparisons, it can be estimated that an additional 14 or 15 lines of hieroglyphic inscription are missing from the top register of the Rosetta Stone, amounting to another . In addition to the inscriptions, there would probably have been a scene depicting the king being presented to the gods, topped with a winged disc, as on the Canopus Stele. These parallels, and a hieroglyphic sign for "stela" on the stone itself (see Gardiner's sign list),
:O26suggest that it originally had a rounded top. The height of the original stele is estimated to have been about .