The cost of a debit measuring device on the market which is fairly expensive raises the idea of making a flowrate measuring instrument that is orifice plate meter with simple construction, easy to install, and inexpensive. This research is expected to provide insight in fluid mechanics and can be applied in the industrial sector with the aim of providing an idea of flowmeter that is easy to use, inexpensive, and high precision value. In this study using PVC pipes with ½ inch and 1 inch diameters and orifice plates made of acrylic with a thickness of 3 mm. Data retrieval method is done by varying the actual flowrate read on the rotameter from 1.5 to 11 LPM with an increase of 0.5 LPM. The pressure difference data that has been obtained is then calculated to get the value of the discharge coefficient and orifice flowrate. The actual flowrate value read in the rotameter is almost equal to the result of the orifice flowrate calculation. The highest flowrate difference on ½ inch pipe occurred in the 3rd experiment of 5%, while the highest flowrate difference in 1 inch pipe occurred in the 2nd experiment by 20%. The value of the discharge coefficient on the two pipes that have been calculated then processed into a percentage of deviations that occur. The highest deviation occurs at reynolds > 7800 numbers exceeding 15%. Assuming ΔCd ≤ 15% then Cd ½ inch is considered equal to Cd 1 inch, then the orifice plate with the same beta ratio can be used to predict the discharge at different pipe size.