Why we calculate Burn-Rate in project?

To have clear understanding of project cost factor and see how the progress is moving

It is very important piece of activity along with other activities during a project, but it is more important in terms of financial scalability and know project status in context to moving ahead in a direction  that was expected or drafted in project plan or any deviation is there. Most importantly it can be framed as

1.Measure

2.Monitor

3. Evaluate

4. Control

To calculate the use of financial resources of key stake holders or share holders or the budget ending point. 

So its a indicator that till what time the project or organization needs funding and by what time it would be making profits, otherwise.....closure

I am with Carmen's answer

Will go with Carmen

Great job Carmen

It is very important factor and driving force for PM

Yes, Carmen