A differential pressure monitor is disclosed herein, which comprises a controller comprising a processor disposed in a housing, and a memory storing instructions that, when executed by the processor, cause the processor to pre-calibrate a first pressure sensor and a second pressure sensor before initial use, and subsequently, determine the differential pressure between the first and second sensors during use of the sensors, and display an indicia representative of the differential pressure between the first and second sensors. Corresponding methods and systems also are disclosed.