- Inflation-adjusted retirement spending target.
- Corpus required using a growing-annuity model.
- Projection of savings and contribution growth.
- Download-ready CSV and PDF reports.
| Scenario | Years | Target corpus |
|---|---|---|
| Balanced | 25 | ≈ 1.2M |
| Conservative | 20 | ≈ 1.6M |
| Aggressive | 30 | ≈ 0.9M |
Formula used
This calculator estimates the required corpus at the retirement date using an inflation-growing withdrawal stream and an assumed post-retirement investment return.
Expense₁ = (MonthlyExpense × 12) × (1 + Inflation)^T × (1 + Lifestyle%)T = years until retirement
PV = Pmt₁ / (r − g) × [1 − ((1 + g)/(1 + r))^N]r = post-retirement return, g = inflation, N = retirement years
RequiredCorpus = (PV + OneTimeGoals + Legacy) × (1 + SafetyMargin%)The “Projected corpus” uses a future-value growing-annuity model for contributions.
r ≈ g, the calculator uses a stable special-case form to avoid divide-by-zero.
How to use this calculator
- Enter your current age, retirement age, and life expectancy.
- Fill in today’s monthly expenses and expected inflation.
- Set pre- and post-retirement return assumptions.
- Add your savings, monthly contributions, and growth rate.
- Optionally include pension income, goals, legacy, and margin.
- Click “Calculate” to see target, projection, and schedules.
- Download CSV or PDF for sharing and record keeping.
Example data table
Use this table as a quick reference for how inputs influence your retirement corpus. Replace values with your own numbers for accurate planning.
| Case | Current Age | Retire Age | Life Exp. | Monthly Expense | Inflation | Post Return | Approx Target Corpus |
|---|---|---|---|---|---|---|---|
| Balanced | 35 | 60 | 85 | $2,000 | 6% | 8% | ~ $1,200,000 |
| Conservative | 40 | 60 | 90 | $2,500 | 7% | 6% | ~ $1,600,000 |
| Aggressive | 30 | 62 | 85 | $1,800 | 5% | 9% | ~ $900,000 |
Building a realistic spending baseline
Start with today’s monthly expenses and split them into essentials. The calculator converts this figure into annual spending, then projects it forward to your retirement date using your inflation assumption and lifestyle adjustment. A lifestyle increase for travel, healthcare, or support for family can change the first retirement-year budget. Use bank statements, utility bills, insurance premiums, and housing costs to avoid underestimating.
Inflation and return assumptions
Inflation drives how fast withdrawals grow each year, while the post-retirement return determines how efficiently the corpus can fund those withdrawals. A higher inflation rate increases the required corpus, and a higher post-retirement return generally reduces it. Keep assumptions consistent with your asset mix and fees. When inflation and return are close, small changes can produce larger swings, so test multiple scenarios and use a safety margin for resilience.
Income offsets and one-time goals
Pension or rental income lowers the net annual need in the first retirement year. If your pension is expected to rise with inflation, enabling inflation linkage will scale it to the retirement date; otherwise it stays nominal. One-time goals, such as debt payoff or relocation costs, are added to the target corpus because they require upfront funding. A legacy goal sets an end value you want to preserve rather than spend down fully.
Contribution strategy and compounding
The projection combines your current savings growth with a contribution stream that can rise each year. This reflects salary progression and step-ups. If the tool shows a shortfall, the estimated required monthly contribution is solved numerically under your assumptions, helping you set a clear savings target. Consider increasing contributions after debt reduction or income jumps, and re-run the model annually to stay aligned with changing markets and goals.
Interpreting the projection tables
The accumulation table shows how your balance evolves from today to retirement, highlighting the role of contributions versus investment growth. The drawdown table simulates retirement years by applying growth and subtracting inflation-adjusted withdrawals. If the closing corpus turns negative in later years, your assumptions imply the plan may not sustain the full horizon. Adjust retirement age, spending, returns, or margin to build a more durable path.
FAQs
1) What does “retirement corpus” mean?
It is the investment amount needed at retirement to fund future withdrawals for your planned years in retirement, after accounting for inflation, returns, and any income offsets.
2) Why are there two return inputs?
Pre-retirement return grows your savings during accumulation. Post-retirement return is applied during withdrawals and can be lower if your portfolio becomes more conservative or if you want to stress-test sustainability.
3) Should I enter nominal or real rates?
Enter nominal rates for both returns and inflation. The model grows expenses using inflation and grows the portfolio using the selected return, so mixing real and nominal rates can distort results.
4) How should I treat a pension?
If the pension increases with inflation, choose the inflation-linked option so it is scaled to retirement. If it is fixed or uncertain, keep it nominal and consider running a second scenario with a reduced value.
5) What can I change if there is a shortfall?
Common levers are: increase monthly contributions, raise the annual contribution growth rate, delay retirement, reduce retirement spending, add pension income, or increase expected returns conservatively. Use the contribution estimate as a target to evaluate trade-offs.
6) How often should I re-calculate?
Re-run the calculator at least annually, and after major events such as salary changes, big purchases, shifts in inflation, or portfolio rebalancing. Regular updates keep your plan aligned with reality and reduce unpleasant surprises.