Is there a way to share the total numbers of hours I plan to spend on a project?

In Toggl Plan, you can currently only add hours per task. We are trying to avoid focusing on hours too much and concentrate more on the general workload a team member has.

If you've already mapped out the whole project, you can use our data export feature to export tasks within a plan to a .csv file to summarize hours planned there. You can read more about how data export works here.
Data export is a paid feature available to Business plan users.