Retirement Corpus Calculator
Estimate the corpus needed for inflation-linked retirement expenses, project your existing savings and monthly investments, and find the shortfall or surplus in your plan.
Last Updated: July 22, 2026Calculate Your Retirement Corpus and Monthly Investment
Use long-term, post-tax assumptions. Every input is editable because inflation, investment returns, income and retirement needs differ for each household.
Enter valid figures and select Calculate Retirement Plan.
Retirement Plan Sensitivity
| Scenario | Inflation in retirement | Post-retirement return | Plan through age | Required corpus | Difference from base |
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Cost of Delaying Investments
| Investment start | Months available | Required starting monthly investment | Increase versus starting now |
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| Year | Age | Opening balance | Contributions | Estimated growth | Closing balance |
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| Retirement year | Age | Opening expense corpus | Annual expense | Other income | Net withdrawal | Closing expense corpus |
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The model uses smooth returns and annual expense increases. Real portfolios experience changing returns, inflation, taxes and withdrawals. Test conservative assumptions and review your plan every year.
What Is a Retirement Corpus Calculator?
A retirement corpus calculator estimates the money you need on the day you retire and compares it with the amount your current savings plan may produce. It connects three parts of retirement planning: future living expenses, the length of retirement and the return expected from your investments.
This version first raises your current retirement expense base for inflation until retirement. It then estimates each year's expense during retirement, subtracts the pension or other regular income entered and discounts the remaining withdrawals at the expected post-retirement return. The emergency or legacy reserve is added separately.
The second calculation projects current savings, monthly investments, annual investment increases and any separate retirement lump sum. You get the required corpus, expected corpus, gap or surplus and the starting monthly investment estimated to meet the target.
This structure follows the main variables used in SEBI Investor's cost-of-delay calculator: expenses, inflation, years to retirement, retirement duration, post-tax return, required corpus and monthly investment. The assumptions remain yours. Market returns are not fixed or guaranteed.
How to Use the Retirement Corpus Calculator
- Enter your current age, planned retirement age and the age through which you want the plan to fund expenses.
- Add current monthly living expenses. Remove loan payments and temporary costs expected to end before retirement.
- Choose the expense replacement percentage. Use 100% if the full current expense base should continue.
- Enter separate inflation assumptions before and during retirement.
- Add a post-retirement return after expected tax and product costs.
- Enter pension income at retirement and its annual increase. Do not include uncertain benefits as guaranteed income.
- Add a reserve for medical shocks, emergencies or an intended legacy.
- Enter current retirement savings, monthly investment, annual step-up, pre-retirement return and any separate future lump sum.
- Review the gap, required monthly investment, sensitivity results, delay cost and both schedules.
Retirement Corpus Formula
The first monthly expense at retirement is estimated as:
Retirement expense = Current monthly expense × Replacement ratio × (1 + pre-retirement inflation)years to retirement
For each retirement year, the calculator increases the expense by post-retirement inflation, subtracts the selected pension income and discounts the net withdrawal back to the retirement date.
Required corpus = Present value of future net withdrawals + emergency or legacy reserve
The model uses beginning-of-year withdrawals. This is cautious because living costs occur throughout the year rather than only after a full year of investment growth. If post-retirement return and inflation are close, the required corpus remains large because purchasing-power growth is limited.
Accumulation Formula
Current savings and monthly contributions compound at the entered pre-retirement return. Contributions occur at month-end. The monthly investment increases once after every 12 completed contribution months. A numerical solver finds the starting monthly amount whose projected corpus reaches the required target.
Worked Example
Consider a 35-year-old planning to retire at 60 and fund expenses through age 90. Current monthly expenses are ₹60,000, the retirement replacement ratio is 80%, inflation is 6%, and the expected post-retirement return is 7%. The plan also keeps a ₹10 lakh reserve.
The first monthly retirement expense rises above ₹2 lakh after 25 years. The required corpus is then calculated from 30 inflation-growing annual withdrawals plus the reserve. Existing savings of ₹10 lakh and a ₹20,000 monthly investment growing 10% each year are projected at a 10% pre-retirement return. Use the live result above for the exact corpus and investment requirement because every input changes the answer.
How Inflation Changes Retirement Expenses
Inflation works twice in this calculation. Before retirement, it raises today's expense to the amount needed in the first retirement year. During retirement, it raises withdrawals each year. A small long-term change has a large effect over 25 or 30 years.
India's official all-India CPI inflation for June 2026 was 4.38% year over year, according to the Ministry of Statistics and Programme Implementation. One monthly reading is not a forecast for a multi-decade retirement. The default 6% is a planning assumption, not an official projection.
Your personal inflation may differ from headline CPI. Healthcare, support services, housing maintenance and travel may form a larger share of expenses later in life. Test at least the base rate and a rate one percentage point higher.
Choosing Return Assumptions
Pre-retirement and post-retirement returns serve different purposes. The pre-retirement rate projects long-term asset growth while you are contributing. The post-retirement rate discounts future withdrawals and models the remaining portfolio after retirement.
- Use returns after expected costs and tax.
- Match the return to the planned asset allocation, not the result you want.
- Do not use a fund's strongest recent return as a long-term assumption.
- Use a lower rate if your retirement portfolio will hold more stable, lower-return assets.
- Check the sensitivity table instead of relying on one result.
A return higher than inflation creates a positive real return. A 7% return with 6% inflation gives a real return of about 0.94%, not 1%, because the exact relationship is (1.07 ÷ 1.06) − 1. When the real return is small, a long retirement needs a substantial starting corpus.
Replacement Ratio, Pension and Reserve
Expense replacement ratio
The replacement ratio decides how much of today's expense base continues into retirement. Some work costs and EMIs may end. Healthcare, home support and travel may rise. Build a retirement budget instead of selecting 80% automatically.
Pension and other regular income
Enter only the nominal monthly income expected at retirement. A pension with no cost-of-living increase loses purchasing power each year. The calculator lets you apply an annual income increase separately from expense inflation.
Emergency and legacy reserve
The reserve is added to the corpus but excluded from routine withdrawals. It may cover medical shocks, major repairs, family support or an intended estate. Do not count the same money both as current savings and as a future lump sum.
Why the Cost of Delay Matters
Starting later reduces the number of contributions and the time each contribution has to compound. The cost-of-delay table keeps the target, current savings, return and step-up assumptions unchanged, then solves for the contribution needed after a one, three or five-year delay.
A delayed contribution must rise sharply when the retirement date is fixed. If the required amount is unaffordable, practical choices include starting with a smaller amount now, increasing it after income rises, reducing expenses, retiring later or adjusting an intended reserve. Raising the assumed return does not fix the underlying funding gap.
How to Build a Stronger Retirement Plan
- Keep an emergency fund outside volatile retirement assets.
- Separate retirement spending from children's education, a home purchase and other goals.
- Include EPF, PPF, NPS and other balances only once.
- Use conservative values for uncertain pension or inheritance income.
- Increase contributions after salary revisions rather than waiting for year-end.
- Review asset allocation, nomination, insurance and withdrawal strategy.
- Recalculate at least yearly and after a major income, expense or family change.
Compare this broad plan with the SEBI annual retirement income calculator. Independent calculations help identify inconsistent inputs. A regulated financial adviser may help where cash flows, tax, property, business income or family responsibilities are complex.
Limitations of This Retirement Calculator
The calculation assumes constant inflation and smooth monthly investment returns. It does not model market crashes, sequence-of-return risk, changing tax rates, fund charges, asset-allocation changes, rebalancing, irregular contributions, withdrawals before retirement or products with lock-ins.
The pension input is simplified regular income. Actual EPF, NPS, annuity, gratuity, government pension and insurance rules differ. The calculator does not determine eligibility, tax exemption, commutation, survivor benefits or product-specific exit conditions.
Retirement expenses rarely rise at one uniform rate. Healthcare and long-term care may grow differently from food, utilities and travel. Life expectancy is uncertain. Use a cautious planning age, add a reserve and test adverse scenarios rather than treating the base result as a precise promise.
Related Retirement Calculators
Use these tools to examine contribution products, pension income and inflation separately.
Frequently Asked Questions
How much retirement corpus do I need?
Your required corpus depends on expenses at retirement, inflation during retirement, pension income, post-retirement return, retirement duration and the reserve you want to keep. Enter your own figures instead of relying on one income multiple.
How does this retirement corpus calculator work?
It inflates current expenses to retirement, values the future net withdrawals at retirement, adds a reserve and compares the result with projected savings and investments.
What inflation rate should I use for retirement planning?
Use a long-term assumption suited to your expense mix and test a higher rate. The 6% default is an editable planning assumption, not an official forecast.
What return should I assume after retirement?
Use an expected post-tax return after costs for the asset mix you expect to hold. A safer retirement allocation may justify a lower assumption than the pre-retirement portfolio.
Does the calculator include pension income?
Yes. It subtracts the entered monthly pension or regular income from retirement expenses and applies the selected annual pension increase.
What does the replacement ratio mean?
It is the percentage of today's monthly expense base expected to continue at retirement before inflation. Review actual categories because some costs end while others rise.
Why is the required monthly investment different from my current SIP?
The required amount is the estimated starting contribution needed to reach the calculated corpus after current savings, annual step-up, return and other retirement lump sum are included.
What happens if post-retirement return equals inflation?
The portfolio has no real growth before tax and costs. The corpus must fund almost the full inflation-adjusted value of each net withdrawal, so the requirement remains high.
How often should I update my retirement plan?
Review it at least once a year and after major changes in income, family needs, expenses, investments, pension benefits, retirement age or tax rules.