A modified equivalent cylinder diameter is proposed for predicting the freezing times of two-dimensional irregular objects. The proposed equivalent diameter was used in predicting the freezing times of ellipses. The predictions using the equivalent diameter was compared with the predictions of a finite difference numerical model and with the predictions of the previously proposed models. The equivalent diameter approach agreed with the numerical data up to 10%. The accuracy of the previously proposed models depended on the centre temperature at the end of freezing.