Assume that the salary increases by 10% each year between age 30 and 40, the annual salary will be 1.1^10=2.59 of it at age 30 by age 40;
To increase the savings from 1 to 2.59*4 from age 30 to 40, one needs to save 2.59*4 - 1= 9.36 annual income of age 30.
Then, how much must be saved annually to achieve this goal?
If one saves 53.5% of the annual income each year since age 30,
0.535*(1.1 + 1.1^2 + … 1.1^10) = 9.38annual income of age 30.
Therefore, in order to achieve “30岁时,你应该存够年薪的1倍;40岁时,你应该存够年薪的4倍;”, one must
1. Keep a 10% income rate every year.
2. Save 53.5% of his/her annual salary.
Do you think this is feasible for most of the people?