Squeezing is time-dependent deformations of tunnels which can cause technical difficulties and financial consequences. This study employs geo-electrical resistivity data to predict squeezing intensity along Beheshtabad tunnel in the Sanandaj-Sirjan formation located in Northwest Iran. For comparison analysis, a combination of semi-empirical approach and numerical modeling was used to evaluate tunnel squeezing at design stage. The squeezing intensity obtained for Beheshtabad tunnel was then compared with the instability observations along Golab tunnel excavated in sedimentary rocks of the same formation. We developed a relationship between electrical resistivity and strains, and provided a new strain-based squeezing classification system. The calibrated electrical data are the most accurate method to predict tunnel squeezing as compared to the conventional approach. The results show that rock type, joint properties and water saturation have noticeable impacts on squeezing.