Calculating Your Retirement Corpus
What is it?
Your retirement corpus is the total investment amount needed at the point of retirement to sustain your desired lifestyle for the rest of your life (or a defined planning horizon), typically estimated by projecting your annual expenses at retirement (adjusted for inflation) and dividing by an assumed safe withdrawal rate, or by using a more detailed year-by-year projection.
Why should you care?
Without an estimated corpus target, retirement saving has no clear finish line — investors either save too little (risking running out of money) or save far more than needed (sacrificing current lifestyle unnecessarily). A calculated target turns a vague goal ("save for retirement") into an actionable, trackable number.
Real-life example
An investor currently spends ₹6,00,000 a year and plans to retire in 25 years. Assuming inflation pushes that expense figure to roughly ₹20,00,000 a year by retirement (illustrative, using a long-term average inflation assumption), and using an assumed safe withdrawal rate of 4%, the target corpus works out to approximately ₹20,00,000 ÷ 0.04 = ₹5 crore — the number the investor now works backward from to determine their required monthly SIP amount.
Common mistakes
- Calculating the corpus based on today's expenses without adjusting for inflation over the full period until retirement.
- Using a single flat withdrawal-rate assumption without considering that expenses (and the corpus's investment mix) may need to change through different phases of retirement.
- Setting the target once and never revisiting it as income, expenses, or market conditions change over a long saving horizon.
Retirement corpus calculation, step by step (illustrative)
| Step | Illustrative value |
|---|---|
| Current annual expenses | ₹6,00,000 |
| Years to retirement | 25 |
| Inflation-adjusted annual expenses at retirement | ≈ ₹20,00,000 |
| Assumed safe withdrawal rate | 4% |
| Target corpus | ≈ ₹5 crore |
FAQ
Should healthcare costs be estimated separately?
Many retirement planners recommend estimating healthcare costs separately since they often rise faster than general inflation, especially later in retirement — folding them into a single blended expense figure can understate this risk.
Does the corpus calculation change if I expect other income in retirement (like a pension)?
Yes — if a pension or other reliable income source covers part of your expenses, the corpus only needs to fund the remaining gap, reducing the required target; see Pension Planning With Mutual Funds for how this fits together.
How often should I recalculate my retirement corpus target?
Periodically — many investors revisit it every few years, or after major life or income changes, since assumptions about expenses, inflation, and investment returns can shift meaningfully over a multi-decade horizon.
Can FundSageAI help estimate my retirement corpus?
FundSageAI's goal-planning tools can help project a target corpus based on your inputs and track progress toward it using your actual portfolio data, making the target more concrete than a one-time manual estimate.
See this concept applied to your own portfolio
Get Started - It's FreeFundSageAI is an analytics platform. Academy lessons are for educational purposes only and do not constitute financial advice. Always consult a SEBI-registered investment advisor for personalised recommendations.