The present work deals with the strength scaling to characterize size effect of the cylindrical ceramic specimen for bimodular materials. The analysis is based on Weibull statistical theory. The derived semi-analytical expressions for effective volume and effective surface area for characterizing volume and surface flaws, respectively, have been validated with the experimental based numerical model. The flexural testing on cylindrical specimens has been done. The characteristic unimodular and bimodular strength has been estimated with different estimators like linear regression and maximum likelihood estimators for two different sized flexural specimens. The strength distribution analysis is controlled by 90% of the confidence interval, and coefficient of determination has been tabulated for goodness of the fit of Weibull distribution curve. The numerical based unimodular and bimodular models have been developed and also its post-processing code has been developed to evaluate the effective volume and surface area numerically. The comparison has been made for different fracture criteria such as principal of independent action (PIA) and normal stress averaging (NSA). © 2020, Springer Nature Singapore Pte Ltd.