Retirement Calculator
Estimate the total retirement corpus you'll need in future, inflation-adjusted rupees, how much your current savings are projected to grow into by then, and the additional monthly SIP required to close the gap.
Fill in the form and select "Calculate" to see your results here.
What is the Retirement Calculator?
Retirement needs to be funded in future rupees, not today's rupees. Whatever you spend each month right now will cost significantly more by the time you actually retire, simply because prices keep rising every year between now and then. Once you do retire, that higher, inflated expense then has to be sustained for potentially decades, and it keeps rising with inflation throughout that period too — a retirement in your 80s costs more per month than a retirement in your 60s, even with no change in lifestyle. This calculator projects both of those numbers: the monthly expense you'll actually face at retirement, and the total corpus required to fund it for as long as you expect to live. It then compares that target against the future value of what you've already saved, and tells you the additional monthly SIP needed to close any gap.
Why a single "today's expenses × years" estimate falls short
A common shortcut is to multiply today's annual expenses by the number of years you expect to be retired. That undercounts the real requirement in two separate ways. First, it ignores that your expenses will be substantially higher in rupee terms by the time you retire — thirty years of even moderate inflation roughly quintuples the cost of the same lifestyle. Second, it ignores that expenses don't freeze once you retire; they keep rising with inflation every year you're drawing down the corpus, so the later years of a long retirement cost far more per month than the early years. This calculator addresses both by inflating your expense forward to your retirement date, and then sizing the corpus using a "real rate of return" annuity — one that accounts for your post-retirement investment return net of ongoing inflation — so the corpus is large enough to keep pace with rising costs throughout retirement, not just at the start.
How to use this calculator
- Enter your Current Age and the Retirement Age at which you plan to stop working — the difference is your remaining investing horizon.
- Enter your Life Expectancy — how far you want your retirement corpus to be planned to last. This determines how many years the corpus needs to sustain.
- Enter your Current Monthly Expenses in today's rupees. The calculator inflates this forward to your retirement date automatically — don't try to estimate future costs yourself.
- Enter your Expected Inflation assumption — the long-term average rate at which you expect prices to rise over your remaining lifetime.
- Enter your Expected Return Before Retirement — the annual return you assume on investments while you're still working and adding to your corpus. This is used both to project your current savings forward and to size the additional monthly SIP.
- Enter your Expected Return After Retirement — usually a lower, more conservative figure than your pre-retirement return, since most people shift toward capital preservation once they start withdrawing from the portfolio rather than adding to it. This rate, together with inflation, determines how large a corpus you need.
- Enter any Current Retirement Savings you already have earmarked for retirement — existing mutual funds, PPF, NPS, EPF or other investments. Leave it at zero if you're starting from scratch.
- Select "Calculate" to see your required corpus, projected future expense, projected value of your current savings, and the additional monthly SIP needed to close any gap.
Methodology
The corpus-sizing step in stage 2 is mathematically a growing annuity — one where the "payment" (your annual expense) itself grows every year at the same rate as inflation. Discounting a growing stream of payments at a nominal rate is equivalent to discounting a level stream at the corresponding real rate, which is why the real-rate annuity factor gives the right corpus size without having to model 25-plus individual inflating withdrawal amounts one by one. Stage 3 reuses the same monthly-SIP future-value formula used across Toolbeel Finance's investment calculators, solved algebraically for the contribution amount instead of the end value. See the editorial policy for how calculation methods are documented and kept current.
Example
Consider a 30-year-old planning to retire at 60, with a life expectancy of 85 — that's 30 years to retirement and 25 years in retirement. Current monthly expenses are ₹50,000, with inflation assumed at 6%, a pre-retirement return of 12%, a post-retirement return of 7%, and ₹10,00,000 already set aside toward retirement.
Inflating ₹50,000 forward by 6% for 30 years gives a future monthly expense of approximately ₹2,87,174.56 (a future annual expense of about ₹34,46,094.70). The real rate of return in retirement works out to (1.07 ÷ 1.06) − 1 ≈ 0.9434%. Applying the growing-annuity factor for 25 years at that real rate to the future annual expense gives a required retirement corpus of approximately ₹7,71,48,478.32. The existing ₹10,00,000, projected forward 30 years at the 12% pre-retirement return, grows to approximately ₹2,99,59,922.12 — leaving a corpus gap of about ₹4,71,88,556.20. Solving for the monthly SIP that closes that gap over the same 30 years at 12% — using the same effective-monthly-rate SIP formula as the SIP Calculator — gives a required additional monthly SIP of approximately ₹15,316.12. Change any of the inputs in the calculator above to see how sensitive this figure is — small changes in the return or inflation assumptions compound significantly over a 30-year horizon.
Factors that affect your retirement plan
- Constant-rate assumptions. This calculator assumes a single constant inflation rate and constant pre- and post-retirement returns for your entire remaining lifetime. Actual markets and inflation vary significantly year to year, and a run of poor early or late returns can affect real-world outcomes very differently from a smooth average.
- Other income sources aren't included automatically. This calculator does not account for other retirement income sources — an EPF balance, an NPS pension annuity, rental income, or a spouse's separate savings — unless you fold their projected value into "Current Retirement Savings" yourself.
- A level SIP, not a growing one. The calculator assumes you continue investing at a fixed, unchanging monthly SIP from today until retirement. In practice, most people's savings capacity grows over their career as income rises, which would let a smaller starting SIP catch up over time.
- No safety margin. The corpus is sized assuming it is fully depleted by the end of your life-expectancy estimate. It does not build in a buffer for outliving that estimate, nor does it account for large one-time expenses such as medical emergencies.
- Related tools. See the FIRE Calculator for an early-retirement-focused alternative that uses a simpler safe-withdrawal-rate rule of thumb, and the Inflation Calculator to explore inflation's effect on a single goal in isolation.
Frequently Asked Questions
Most people invest more aggressively while they're still working, since they have decades to ride out market ups and downs. After retirement, many shift toward a more conservative mix — favoring capital preservation and steady income over growth — because they're now withdrawing from the portfolio rather than adding to it. Using two separate rates lets you model that shift instead of assuming the same risk profile for your entire life.
If the projected future value of your current retirement savings already meets or exceeds the required corpus, the corpus gap is zero and the calculator shows that you're already on track — no additional monthly SIP is needed based on the assumptions you entered. This can happen with a large existing corpus, a long remaining investment horizon, or a high assumed pre-retirement return, and it's worth stress-testing with more conservative return assumptions before relying on it.
The FIRE Calculator uses a simpler rule of thumb — typically a 25x-expenses target based on a safe withdrawal rate — aimed at people planning an early, self-funded retirement. This Retirement Calculator does a fuller projection: it inflates your expenses forward to your actual retirement date, sizes the corpus using a real-rate-of-return annuity that keeps pace with inflation throughout retirement, and accounts for your current savings and remaining working years. Use FIRE for a quick early-retirement target, and this calculator for a more detailed, longevity-adjusted plan.
Not automatically. This calculator only looks at the "Current Retirement Savings" figure you enter and the monthly SIP you'd need going forward. If you expect EPF, NPS annuity income, rental income or a spouse's separate savings to contribute toward retirement, fold their projected value into the "Current Retirement Savings" input yourself — for example, by first running the NPS or EPF calculator and adding the resulting corpus figure here.
Two forces compound together: your expenses are inflated forward by however many years remain until retirement, and the corpus then has to keep pace with inflation across every year you're retired, not just grow at a flat rate. Sizing the corpus using a real rate of return (your post-retirement return net of inflation) captures both effects, which is why the number is typically much larger than simply multiplying today's expenses by your remaining years.
Related calculators
This calculator provides a long-term projection based on several rate assumptions — inflation, and returns before and after retirement — that will not play out exactly as assumed in the real world. It is not a substitute for professional financial planning advice. See our full disclaimer.