A retirement corpus is the total sum of money you've accumulated by the time you retire, intended to fund your living expenses, healthcare, and lifestyle for the remainder of your life once regular income from work stops. It's typically built up over decades through a combination of instruments like EPF, PPF, NPS, mutual funds, and other long-term investments.
Figuring out how large a retirement corpus you actually need depends on factors like your expected monthly expenses after retirement, how many years you expect to live post-retirement, and an assumed inflation rate that will erode the value of your money over that time. Tools like a Goal Planner can help estimate this by projecting your current expenses forward with inflation and calculating how much you'd need to save regularly, starting now, to reach that target.