Urodynamics measurement tools in practical use carry the risk of nosocomial infection and invasiveness. Our study proposes a new method for urinary flow estimation. We propose multiple cylindrical model to estimate the amount of liquid volume from images taken by a monocular camera. This model is based on the idea of calculating the total volume of cylinder extracted from each image. First, images of liquid simulating male urination are binarized to derive features for the model. Each volume of cylinder is calculated by the initial velocity and diameter of liquid in each image. We conducted experiments to evaluate the model by comparing our estimated volume and flow rate to the data acquired from uroflowmeter in practical use. As a result, estimation was within the accuracy of ±10% which is enough accuracy of actual uroflowmeter being used in Japanese hospitals for practical use.