PVC is a type of thermoplastic material which affected by heat due to the presence of chlorine and which is not used alone but with addition of additives such as stabilizers, plasticizers, fillers and others according to the required properties of the desired product based in suitable formulations. In this work many experiments were carried out to evaluate the additives and the type of PVC used on the formulation in cables application. The first experiments were to vary the amount of filler (calcium carbonate) and that ingredients such as PVC K67 resin, lubricant (stearic acid), stabilizer (tri-base lead sulfate), and plasticizer (Dioctyl phthalate) were constant in the formulation and then samples were tested for density, hardness, tensile strength, and sample burn test to determine the content of fillers or plasticizers. The results of the density test showed that it was 23.91wt% of the filler and in the hardness test, the plasticizers used were estimated at 52.61wt%. The tensile test results were 10.6 wt% of filler when the plasticizer value was 60wt% or 20wt% of filler with 65wt% of plasticizer weight. And it turned out that the unknown sample used PVC and high molecular weight such as pvck70-72 and not Pvck67 which we used in all experiments and the result of burning the sample gave 21.9% of the ash which is a filler. In the second experiments, the stabilizer was changed and the rest of the components were considered fixed, and the result was that the weight of the stabilizer was less than the lowest value used in the experiments 6wt% and finally. The study concluded that the sample used high molecular weight PVC, the filler percentage was 20wt%-23.9wt%, and the plasticizer was 52.61wt%-65.7wt%. This study shows that the proportions of the components of the PVC formulation can be estimated by studying the effect of fillers and heat stabilizers by using mechanical tests.