Auto allocate % of project to tasks and auto calculate project completion

Hi all
Getting to grips with smartsheets and had a question.
Is it possible to auto calculate the % each task and sub task counts towards a project and also calculate how much % the project is complete based on completed tasks (hope that makes sense!)
For example. I have a project with 5 workstreams and each workstream as between 10-15 tasks.
So each workstream counts to 20% of the project (5x 20% = 100%)
Within each workstream, the sub tasks would have their own % count towards the 20% so if the workstream had 10 tasks, each task would be 2%.
There is also a running total of how much the project is completed, so as each task gets completed, this total would go up until all tasks are completed and the project is 100%
If more sub-tasks are added to the workstream, Smartsheets can auto calculate the new % each task is worth.
Thanks