This thesis looks into the current method a particular company uses to value its inventory carrying costs (ICC). By identifying costs incurred during all stages of production, along with incorporating industry standards and academic research while avoiding the shortcomings of the company's current method, this thesis was able to derive a more comprehensive and manageable tool for measuring ICC. Our findings led to concrete recommendations, which will provide real value to company managers by improving the accuracy of project finance calculations, supply chain optimization modeling, and numerous other decisions relying on accurate inventory data inputs.