Calculating your retirement corpus needed is straightforward once you know the Retirement formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Retirement Calculator.
What is Retirement?
The Retirement calculation tells you your retirement corpus needed from a few simple inputs. The figure you are solving for here is the retirement corpus needed, expressed in INR.
The Retirement formula
The core formula is:
Retirement corpus needed = Current monthly expense × (1 + Inflation (p.a.) ÷ 100)^(Years to retirement) × 12 × Years in retirementHere is what each input means:
- Current monthly expense — a money amount. Example: ₹50,000.
- Years to retirement — a value you set on the slider. Example: 25 years.
- Inflation (p.a.) — a percentage, such as an annual rate. Example: 6%.
- Years in retirement — a value you set on the slider. Example: 25 years.
How to calculate it step by step
- Write down the current monthly expense (for example, ₹50,000).
- Note the years to retirement (for example, 25 years).
- Write down the inflation (p.a.) (for example, 6%).
- Note the years in retirement (for example, 25 years).
- Apply the formula above to get your retirement corpus needed.
- Double-check the result with the Retirement Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Current monthly expense | ₹50,000 |
| Years to retirement | 25 years |
| Inflation (p.a.) | 6% |
| Years in retirement | 25 years |
| Monthly expense at retirement | ₹2,14,594 |
| Retirement corpus needed | ₹6,43,78,061 |
With current monthly expense of ₹50,000, years to retirement of 25 years, inflation (p.a.) of 6% and years in retirement of 25 years, the retirement corpus needed works out to ₹6,43,78,061.
Example 2
With current monthly expense of ₹1,00,000, years to retirement of 25 years, inflation (p.a.) of 6% and years in retirement of 25 years, the retirement corpus needed works out to ₹12,87,56,122.
| Result | Value |
|---|---|
| Monthly expense at retirement | ₹4,29,187 |
| Retirement corpus needed | ₹12,87,56,122 |
Example 3
With current monthly expense of ₹25,000, years to retirement of 25 years, inflation (p.a.) of 6% and years in retirement of 25 years, the retirement corpus needed works out to ₹3,21,89,030.
| Result | Value |
|---|---|
| Monthly expense at retirement | ₹1,07,297 |
| Retirement corpus needed | ₹3,21,89,030 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
- Annual rates must be converted to the period you are calculating for (for example, divide an annual rate by 12 for a monthly figure).
Prefer not to do the maths by hand? — the Retirement Calculator does it instantly, for free, with the formula and a worked example built in.
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