Retirement corpus calculator

How much do you need to invest today, as a one-time lump sum, to draw a chosen monthly income through retirement — with the pot lasting exactly to your planned age? Set your income and ages, tune the return/inflation assumptions, and see a year-by-year breakdown. Defaults are India-flavoured. Everything runs in your browser.

Desired monthly income This income is in

Current age Retirement age Income needed until age

Assumptions (editable)

Equity return % p.a. Debt return % p.a. Inflation % p.a. Equity % before retirement Equity % after retirement

Invest this lump sum today —

Corpus at retirement

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Blended return pre / post

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First-year income (monthly)

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Final-year income (monthly)

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Total withdrawn over retirement

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Years saving / drawing

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Portfolio & withdrawals by age

Portfolio value Annual withdrawal ┊ retirement age

Year-by-year breakdown

Age	Opening	Withdrawn	Returns	Closing	Net change

How this is worked out

Returns are blended from your equity / debt split: with the defaults that's 14% while you're accumulating (100% equity) and 10.8% in retirement (60% equity, 40% debt). Your desired income is taken in today's money, inflated to the retirement date, then grown by inflation every year of retirement so your real spending power stays flat.

The lump sum is sized so the portfolio is drawn down to exactly zero right after the final year's withdrawal. Withdrawals are taken at the start of each year, from your retirement age through the final age, inclusive. The corpus needed at retirement is the present value of that rising income stream at the post-retirement return; discounting it back at the pre-retirement return gives the amount to invest today.

These are nominal-return projections under fixed assumptions — markets don't deliver steady returns, sequence-of-returns risk is real, and taxes and fees aren't modelled. Treat the figure as a planning estimate, not a guarantee, and revisit it as your situation changes. Not financial advice.