Use Case Point (UCP) is one of many approaches used for software project estimation. This approach is implemented by calculating effort estimation based on prediction a total number of workers and software development time. UCP was fist introduced by Karner on 1993. This approach is widely used. It was because some research on UCP showed that UCP approach is better than those approaches developed by experts. The calculation of effort estimation that was mentioned in the paper (Chetan Nagar, 2011), it has been proven that calculation estimation using UCP sometimes doesn't fit the real effort. This leads to the difference in cost calculation and a total number of workers on software development project.