Devices and methods for measuring roller chain wear are provided. A roller chain wear gauge may include an elongated structure configured to be inserted into a gap between two roller links of a chain joined by a pin link of the chain, the chain having an associated chain size. The elongated structure may include a first side surface, a second side surface, a length extending along a longitudinal axis of the elongated structure, and a plurality of widths located along the length and defined by and between the first and second side surfaces. The first side surface may extend at an angle relative to the longitudinal axis such that the plurality of widths continuously tapers over the length. The plurality of widths may be calibrated against a reference chain representative of the associated chain size.