Predicting the equivalent settling area of the hydrocyclones is important for selection and design of the device. It also allows comparison of hydrocyclone to other separators that work using a similar concept. A mathematical model based on the physics of the separation phenomenon in the hydrocyclone is developed to predict the equivalent area factor of the hydrocyclone. The effect of the overflow and inlet diameters on the hydrocyclone performance are evaluated and it is shown that changing the overflow diameter has more effect on the equivalent area factor than the inlet diameter. The equivalent settling area model (ESAM) is validated with experimental data from experiments using a 50 mm diameter hydrocyclone and glass bead particles. Good agreement between ESAM and the experiments is observed. An advantage of ESAM is that it can be used to estimate the tangential velocity profile in a hydrocyclone. A method of predicting the tangential velocity profile on the basis of equivalent settling area without performing velocity measurement is detailed and examined for an experimental velocity profile. This allows the ESAM to be used as a framework for design of the hydrocyclone devices. Crown Copyright (C) 2016 Published by Elsevier B.V. All rights reserved.