The exact size of Sasuke Uchiha's Kusanagi Sword in the Naruto series is not explicitly specified. However, based on its depiction in the anime and manga, it can be described as a medium to long-length sword.

The Kusanagi Sword typically possesses a straight, single-edged blade that extends from the hilt. While the specific measurements may vary depending on the artist's interpretation, it is generally portrayed as being shorter than a traditional katana but longer than a standard ninja sword (ninjato).

In terms of proportions, the sword's length is typically depicted to be roughly comparable to Sasuke's height or slightly shorter, allowing for effective use in close-quarters combat and swift strikes.

It's important to note that the precise dimensions of Sasuke's Kusanagi Sword can vary slightly depending on the artistic style and portrayal in different scenes and adaptations within the Naruto series.