Monkey D. Luffy's stretching ability, derived from his Gomu Gomu no Mi (Rubber) Devil Fruit powers, has been humorously and variably described by Eiichiro Oda, the creator of One Piece, in SBS (author Q&A) sections. According to Oda, Luffy can stretch about 72 Gomu Gomus, though the exact length of a "Gomu Gomu" unit is not officially defined and seems intentionally vague

. Fan calculations and interpretations suggest a wide range of possible distances:

• A common estimate is around 72 to 74 Gomu Gomus, which some fans equate to roughly 300 meters to a few kilometers based on scenes in the manga where Luffy stretches to save Usopp or in battles

• More speculative and humorous fan calculations propose that if one Gomu Gomu is interpreted as a cosmic distance unit, Luffy could theoretically stretch anywhere from about 90 kilometers up to over 5,000 kilometers, even jokingly suggesting he could stretch to the moon or Raftel (the final island in the One Piece world)

• Oda himself has joked about the difficulty in pinning down an exact measurement, implying the numbers are more playful than canonical

Practically, in the story, Luffy's stretch has limits-he has been shown to nearly tear his skin when pushing his stretching too far, such as during the Whole Cake Island arc

. His maximum effective stretch in combat or rescue situations is likely a few hundred meters to a couple of kilometers at most, with his advanced Gear Fourth forms enhancing his reach further

. In summary, canonically, Luffy can stretch about 72 Gomu Gomus, which roughly translates to several hundred meters, but fan interpretations and Oda's playful answers allow for a much broader, less literal range.