In this paper, a comprehensive study of the strength of lime treated soft clays is made. There are three major factors that affect the strength of the soils; they are the lime content, curing time, and curing temperature. The variations of soil strengths with the three factors are analysed and quantified via proposed empirical equations. These equations are verified against experimental data. Finally, a general strength criterion, unifying the influence of all the three factors into a single equation, is proposed. The capacity of the general equation is also demonstrated. It is seen that the proposed strength equations can provide a useful means for predicting the strength of lime treated clays under various conditions.