There is a calculator which estimates whether one can quit his/her day job at the prevailing circumstance. Such calculator can also forecast the amount of time in which one needs to work at the current job based his/her existing income.
I find the above calculator quite useful and it will determine as one of the reference point in which one can consider planning the exit from the corporate rate race he/she deem fit. For those who are happy with his/her existing work, this can be used as a reference point. No one can determine whether the existing work condition will remain the same as the time passes. Circumstance is dynamic in the existing world. This is one of the options in which one can take in the event if the work circumstance becomes not as rosy as the present in future. The website link is as follows: