To provide a pipe cutting tool for quickly installing a cutting edge in a predetermined position of a flexible tube.

This pipe cutting tool 1 has: a base body part 22 for wrapping and holding the flexible tube 10 and having guide rollers 23 and 24 abutting on an outer peripheral surface of the flexible tube 10; a hook-shaped member 2 having a gripping part 21 extending in the direction for crossing the flexible tube 10; and a movable member 4 projected toward the guide rollers 23 and 24 from the gripping part 21. The movable member 41 has: a column part 41 capable of adjusting the length of a part projecting from the gripping part 21; a shaft 43 supported by the column part 41 and extending in the shaft direction of the flexible tube 10; a disk-like cutting edge 44 journled there; guide rollers 45 and 46 having a diameter smaller than the cutting edge 44 journaled by sandwiching the cutting edge 44; and a gauge member 5 journaled to the end part side of at least one guide roller 45. The gauge member 5 has a display part 52 forming graduations 53, 54, 55 and 56 for displaying respective diameters in a plurality of positions corresponding to a diameter of the flexible tube 10.