Your estimation would change for each project since every project is different. You also have to determine what type of project it is (new, maintenance, etc). I listed below some key items I use when I try to plan out a project:
1. Number of requirements
2. Number of change requests
3. Complexity of the application
4. Is any training needed (application, process, etc.)?
5. Testing types needed (manual, automated, performance, etc)
6. Planning and preparation
7. Number of test cases to be created (happy path & negative)
8. Number of test cases to be updated
9. Automated scripts to be updated
10 Performance scripts to be created
11. Number of hours for testing
12. Number of hours for retesting and defect fixes (this is huge since I have found that most of the time project teams don’t include and it does take time to go back and retest any fixes)
13. Number of resources available/needed
14. Number of working hours that can be dedicated to the project (most resources are on multiple projects)
15. Number of meetings for the project (I always think this is important because if you’re in constant meetings you’re not getting any testing done which impacts your timelines)
16. Determine the reporting styles and when they need to be completed.