SWP: Turning a Corpus Into a Monthly Income

At retirement, most people do not need a large lump sum. They need a reliable monthly income. A systematic withdrawal plan does exactly that: you keep the corpus invested and redeem a fixed amount every month.

How it works

You invest a lump sum in a mutual fund and set up a monthly withdrawal. Each month the fund house redeems units and pays you the amount. The rest of the corpus stays invested and keeps growing.

The maths is straightforward. Each month the balance grows by the return and shrinks by the withdrawal. Our SWP calculator projects the balance, the total withdrawn, and how long the money lasts.

The withdrawal rate decides everything

Divide your annual withdrawal by the corpus to get the withdrawal rate, and compare it with the return.

• ₹30,000 a month on ₹50 lakh is ₹3.6 lakh a year — a 7.2% withdrawal rate. With an 8% return, the corpus survives and still grows slightly.
• ₹50,000 a month on the same corpus is a 12% withdrawal rate. With an 8% return, the corpus must fall every year, and it will run out.

Run ₹50 lakh, ₹30,000 a month and 8% through the calculator and after twenty years you have withdrawn ₹72 lakh and the corpus is still around ₹69.6 lakh. The withdrawal rate is below the return, so the money compounds faster than it leaves.

Sequence risk: the part projections miss

A projection assumes a steady 8% every year. Real markets are not steady. If the first three years of retirement deliver poor returns while you keep withdrawing, the corpus is permanently smaller, and later good years have less to work with. Two portfolios with the same average return can end up in very different places depending on the order.

The practical defence is a cash buffer: keep one to two years of withdrawals in a liquid fund or short deposit. Then you are not forced to sell equity in a falling market just to pay the monthly bill, and you can top the buffer up in good years.

SWP versus the alternatives

• Annuity. Guaranteed income for life, but low rates — roughly 5–6% — and the money is locked away. Good for certainty, poor for flexibility or legacy.
• FD interest. Predictable, but fully taxable at your slab, and the real return is often close to zero after inflation.
• SWP. Only the gain portion of each withdrawal is taxed, the capital stays accessible, and the balance remains yours. Market risk and discipline are the trade-offs.

A sensible way to set it up

• Keep the withdrawal rate modest — start near 4% of the corpus and review annually.
• Hold a cash buffer of one to two years of withdrawals outside the SWP.
• Increase the withdrawal gradually with inflation rather than fixing it for twenty years.
• Review the plan every year, and reduce the withdrawal slightly after a very poor year instead of panic-selling.

Run the numbers first in the SWP calculator, and use the retirement calculator to check whether the corpus you have is enough for the income you want. Getting the withdrawal rate right matters far more than chasing an extra percentage point of return.