SWP Calculator — How Long Will Your Corpus Last?

How to use the SWP calculator

1. Enter your Invested corpus, the amount you start with.
2. Enter the Monthly withdrawal you want to take.
3. Enter the Expected return (per year).
4. Pick your currency.
5. Read how long the corpus lasts, the total you withdraw, and the monthly return on your starting corpus. The chart and table show the balance at the end of each year.

What it does and when to use it

An SWP turns a lump sum into a regular income. People use it in retirement, to fund a child’s college years, or to draw a steady amount from a maturity payout. The key question is always the same: if I take this much every month, how long will it last?

This calculator answers that by playing out the plan one month at a time. It is a planning aid for comparing scenarios, such as a smaller withdrawal, a bigger corpus or a more cautious return. It does not predict what a real fund will earn.

To build the corpus in the first place, see the SIP Calculator or the Lumpsum Calculator. For a whole retirement plan, try the Retirement Savings Calculator.

How it works

The monthly return is i = yearly return ÷ 12 ÷ 100. Each month the tool:

1. Withdraws your monthly amount (or whatever is left, if that is less).
2. Grows the remaining balance: new balance = (balance − withdrawal) × (1 + i).

It stops when the balance reaches zero, or after 100 years. The monthly return on the starting corpus is corpus × i. If your withdrawal is clearly below that figure, the balance grows. Because each withdrawal comes out before the month’s growth, a withdrawal only just under it can still wear the balance down very slowly. The calculation runs in your browser.

Worked examples

₹50 lakh, withdrawing ₹40,000 a month at 8%. The starting corpus earns ₹33,333.33 in its first month, less than the withdrawal, so the balance slowly falls. Corpus lasts: 22 years 1 month, and the total withdrawn is ₹1,05,90,268.99, about twice the starting amount.

₹50 lakh, withdrawing ₹30,000 a month at 8%. Now the withdrawal is below the monthly return of ₹33,333.33, so the balance keeps growing. The result is Corpus lasts: 100 years or more (does not run out).

The difference between these two plans is ₹10,000 a month, yet one runs out and the other does not. Small changes in the withdrawal or the return make a large difference over decades.

Limits and tips

• The return is the same every month. Real funds rise and fall, and a run of bad years early in an SWP hurts more than the same years later on.
• Withdrawals are taken at the start of each month, before growth. To see how the same corpus would grow with no withdrawals, use the Compound Interest Calculator.
• Tax, exit loads and fund expenses are not included.
• To see how inflation eats into a fixed withdrawal, use the Inflation Calculator.