This study explores a method of finding latent heat of all types of phase transitions of Octylcyanobiphenyl (8CB) liquid crystal where transitions can be ranged from strong first order transition to weak first order and/or second order phase transition. The role of latent heat is very important in Physics, Chemistry and Physical Chemistry area to find how much heat is needed to change the transition of the material. Some of the materials show phase transitions with wings, inclined lines or slopyness that come from the base data and may bring an issue in finding and calculating latent heat for them. In this work, we are focusing on types of phase transition with or without wings to find their latent heat with improved methods and calculations. 8CB is a good example that shows three phase transitions of each type, i.e. crystalline to smectic A transition (K-SmA) which is a strong first order transition, smectic A to nematic (SmA-N) which is a second order phase transition and nematic to isotropic transition (N-I) which is a weak first order transition. These transitions are discussed to use a developed method of finding latent heat of various types of transitions with precision. The latent heat of K-SmA phase transition is found to be the highest, SmA-N is the lowest whereas N-I is in the intermediate range which satisfies the fact that stronger phase transitions need higher latent heat than the weaker phase transitions. This study also shows a correlation between other thermodynamic parameters of these phase transitions in terms of heat flow, heat capacity, specific heat capacity and enthalpy along with their thermodynamic behavior.