We don't currently have a worksheet for students, here in the PrepCast team. Now the application is completed online, you can fill in your experience directly into the PMI system. However, there is a detailed article on our blog about how to fill in your PMP application with a section on how to calculate working hours, which might help:
www.project-management-prepcast.com/how-...-the-pmp-application
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®