Uber is revolutionising transportation in cities as it promises to take hundreds of thousands of cars off the roads in years to come. And it has made itself incredibly rich in the process, with the most recent funding round pegging the driver-on-demand startup as worth an estimated $40 billion.

Morgan Stanley has now estimated exactly where Uber customers' cash goes. Just 50% actually goes into the driver's pocket, with fuel, insurance and finance charges among the other costs. Uber's own fee is the single largest cost after salary, taking 20% of the total.

Of course, the breakdown may be like this forever. Uber is investing heavily in self-driving car technology, and has hired dozens of Carnegie Mellon scientists to work on the issue. When the technology comes to fruition, it could save billions in costs — and make thousands of contracted drivers redundant.