How Retirement Corpus Planning Works
A retirement projection connects two periods. During accumulation, current investments and regular contributions may compound until retirement. During retirement, the corpus may continue earning returns while funding withdrawals that rise with inflation. The result is sensitive to every assumption, especially time, expenses, inflation, returns, contribution growth, and retirement duration.
SEBI investor education emphasizes planning early, accounting for expenses and inflation, maintaining emergency and insurance protection, and considering diversification. This calculator provides an educational projection—not a product recommendation or assured outcome.
Official reference: SEBI Investor—Plan Early for Retirement.
Inflation and Future Retirement Income
The expense and other-income fields are entered in today's purchasing power. Both are compounded to retirement at the entered inflation rate. The difference becomes the first modeled withdrawal, which then continues increasing monthly with inflation through retirement.
Future Monthly Expense
Expense today × (1 + inflation)years
Net Corpus Withdrawal
Future expense − future other income
Return Assumptions and Compounding
The calculator converts each annual return to an equivalent monthly compounded rate. Contributions are added at month end, and the selected annual contribution increase is applied after every 12 months. Retirement withdrawals occur after the month's modeled return.
Investor.gov provides compound-interest and savings-goal tools using initial investment, monthly contribution, time and estimated interest-rate assumptions. Here, those concepts are extended into a retirement drawdown phase.
Official reference: Investor.gov Compound Interest Calculator.
Understanding the Main Results
Projected corpus
Estimated savings available at retirement from the entered current corpus, contribution path and pre-retirement return.
Required corpus
Present value at retirement of the complete inflation-linked withdrawal path plus the desired legacy.
Required monthly contribution
Estimated starting contribution needed to close the corpus gap while preserving the entered annual contribution increase.
Sustainable monthly income
Maximum modeled starting net withdrawal supported by the projected corpus while retaining the legacy target.
Why Compare Return Scenarios?
The lower and higher scenarios shift both entered return assumptions by two percentage points while holding other inputs constant. This illustrates sensitivity but does not model the order of gains and losses. Real portfolios experience volatility, and poor returns early in retirement can materially reduce corpus longevity.
Important: Projection, Not Financial Advice
This model assumes smooth monthly returns and inflation. It does not independently calculate fees, taxes, insurance, healthcare shocks, market volatility, sequence-of-returns risk, contribution interruptions, or product restrictions. Investment returns are not guaranteed, values can rise or fall, and past performance does not guarantee future performance. Use conservative assumptions, test multiple scenarios, review the plan regularly, and consult a qualified regulated professional when appropriate.
Risk reference: AMFI—Risks in Mutual Funds.