[header] How to calculate man hours [title] Divide your project into components. [step] The first part of calculating the man-hours you will need to do a job is to split up the project into smaller components. Then estimate the amount of hours needed to complete each component. 
These components should be designated according to the type of labor involved. If you are building an apartment complex, you will need excavation, construction, electrical, plumbing, and so on.