Retirement planning: How to calculate retirement corpus SECTIONS Share Synopsis The sooner you want to retire, the longer will be your post retirement life. As a result, on one hand, you will have to arrange a bigger retirement corpus for a longer retired life, and on the other hand you will have lesser time to save the required amount. Getty Images Saving for retirement is possibly one of the most important financial goals. This is because accumulating an adequate corpus will help one live a financially comfortable life post retirement. And knowing how much to save, will help during the pre-retirement phase, i.e., the accumulation stage. So, how does one decide how much to save for retirement?