SWP calculator
How long the money lasts when it is being drawn down and still invested at the same time.
The maths
How this is calculated.
Each month the balance grows and then a withdrawal is taken from it, so the corpus is stepped forward one month at a time:
Bₙ₊₁ = Bₙ × (1 + i) − W
Where B is the balance, i the monthly return and W the withdrawal. The corpus is exhausted the first month the balance reaches zero.
There is a threshold worth knowing: where B × i ≥ W, growth covers the withdrawal and the corpus is never drawn down at all. Below it, the balance falls slowly at first and then quickly, because each withdrawal also removes the growth that money would have earned.
What it assumes. A constant return and a withdrawal that never rises. Both are optimistic — see the FAQ on sequence risk.
Worked example
₹ 1 crore, and where the threshold sits.
At an assumed 8 % a year, ₹ 1,00,00,000 earns about ₹ 66,667 a month. Draw ₹ 60,000 and growth more than covers it — the corpus is never drawn down at all, and the calculator says so rather than quoting a number of years.
Cross that threshold and the arithmetic turns sharply. At ₹ 80,000 a month the same corpus lasts about 22 years and 6 months. At ₹ 90,000 — twelve per cent more — it lasts about 17 years. Five and a half years gone for a ₹ 10,000 difference in the monthly draw.
That is the shape worth understanding before setting a withdrawal: it is not linear, and the steepest part of the curve is immediately after the point where growth stops covering the draw.
Questions about this calculator.
What is a safe withdrawal rate?
The often-quoted 4 % a year comes from American equity and bond history and does not transfer cleanly to India. What this calculator can tell you is the arithmetic: at what withdrawal your corpus survives a given return, and how sharply that changes when either moves.
What is sequence risk?
The order of returns matters when you are withdrawing, in a way it does not when you are accumulating. Two decades with the same average return produce very different outcomes if one starts with a crash — you sell units cheaply to fund the withdrawal and they are not there to recover. This calculator assumes a constant return and therefore understates that risk.
Should the withdrawal rise with inflation?
In practice yes, and a fixed withdrawal loses purchasing power every year. A rising withdrawal exhausts a corpus considerably sooner than this shows. An inflation field is on the list for this page.
Does it account for tax?
No. Each withdrawal from an equity fund realises a gain that is taxable, so your after-tax income is lower than the withdrawal shown. The capital gains calculator handles a single redemption.
Is my input sent anywhere?
No. The calculation runs in your browser. Nothing is submitted, stored or logged.
From the team behind Finvica — the operating platform for multi-product wealth practices. See the platform