Abstract: This invention provides a fluid flow meter including an elongated tube and an element adapted for connection to a fluid line, the elongated tube including one or more orifice openings of predetermined area, and indicia correlated with the area of the orifice opening for providing a reading of fluid flow dependent upon the level to which fluid rises in the elongated tube.In one embodiment the tube includes a plurality of scales for indicating different ranges of flow rates, and an orifice opening corresponding to each of said scales, said orifice openings being of different areas and selectively openable so that said scales can individually be made to show fluid flow rates.