SWP Calculator

See how long your mutual fund corpus lasts at a fixed monthly withdrawal.

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Calculation Examples

Calculation Case Result
$100,000 corpus, withdraw $1,000/month at 8% annual return Corpus lasts about 13.8 years (165 months)
$500,000 corpus, withdraw $2,000/month at 6% annual return Corpus grows (monthly return of $2,500 exceeds the withdrawal)
Breakeven withdrawal on $300,000 at 7% annual return $1,750/month (corpus stays level)
Mihail Doncenco
Mihail Doncenco Site Creator & Calculator Expert

Founder and developer of CalcMate. Builds and maintains every calculator on this site, focusing on formula accuracy and clear, practical results.

How to Use the SWP Calculator

Enter your starting corpus, the amount you want to withdraw each period, and the annual return you expect on the money that stays invested. Monthly withdrawals are the usual choice for retirees, and quarterly and annual options are also available.

Click "Calculate" to see how long the corpus lasts, the balance after each period, and the total withdrawn. The result is a projection for planning, not a guarantee, and not investment or tax advice.

How SWP Calculations Work

Each period, the remaining corpus earns that period's return, and then the withdrawal comes out: \[ B_n = B_{n-1}(1 + r) - W \] Here \(B_n\) is the balance after the \(n\)-th withdrawal, \(r\) is the periodic return (the annual rate divided by 12 for monthly), and \(W\) is the withdrawal. The calculator assumes withdrawals at the end of each period and ignores taxes, fees, and exit loads. When the periodic return on the corpus, \(Pr\), is larger than \(W\), the corpus grows. When \(W\) is larger, it shrinks until it runs out. The breakeven withdrawal is \(W = Pr\): for $300,000 at 7% a year, that is $300,000 times 0.07 divided by 12, or $1,750 a month.

Real returns are never smooth. A bad market in the first few years of retirement hurts far more than the same losses later, because you sell units at low prices while the corpus is still large. This is called sequence-of-returns risk, and it is why you should stress-test a plan with lower returns than you hope for.

Difference Between SIP (Systematic Investment Plan) and SWP (Systematic Withdrawal Plan)

Useful Tips 💡

  • Use a return you can defend, not a best-case figure. Test at least two rates, such as 8% and 5%, and plan around the lower result. A single bad year early in retirement can shorten the life of the corpus noticeably.
  • Adjust for inflation by looking at the real return. A 7% nominal return with 3% inflation is a real return of about 3.9% (1.07 divided by 1.03, minus 1). If your spending rises with prices, plan with that lower number.

📋Steps to Calculate

  1. Enter your total invested corpus and the expected annual return rate.

  2. Enter your desired withdrawal amount and frequency (monthly, quarterly, or annual).

  3. Click "Calculate" to view the projected corpus balance over time and the estimated number of periods until depletion.

Mistakes to Avoid ⚠️

  1. Never revisiting the plan. As markets move, the corpus and the sustainable withdrawal change, so recalculate at least once a year.
  2. Ignoring inflation over a long horizon. A fixed withdrawal of $2,000 a month keeps the purchasing power of about $1,488 after 10 years and $1,107 after 20 years at 3% inflation.
  3. Starting too high. Historical US studies, including the 1998 Trinity Study, found that withdrawing about 4% of the starting portfolio in the first year, then adjusting for inflation, held up over most 30-year periods. Starting rates of 5% to 6% failed noticeably more often.
  4. Forgetting taxes. In a taxable account, the gain portion of each withdrawal can be taxed in the year you receive it, so net income is lower than the gross withdrawal.

Practical Applications📊

  1. Plan retirement income: a $500,000 corpus at 7% a year with $4,000 withdrawn each month lasts about 18.7 years. Cutting the withdrawal to $2,900 or less keeps the corpus from shrinking.

  2. Stress-test the return: $500,000 with $3,500 withdrawn monthly lasts about 38 years at 8%, 21 years at 6%, and 16 years at 4%. The same plan looks safe or fragile depending on one assumption.

  3. Set a benchmark: a 4% starting withdrawal on $1,000,000 is $40,000 a year, or about $3,333 a month. Compare your planned withdrawal with this figure.

  4. Compare income options: run your SWP numbers next to an annuity quote or a lump-sum withdrawal, and then weigh tax treatment, liquidity, and how much longevity risk you can accept.

Questions and Answers

How do you calculate how long an SWP corpus will last?

Use \(n = -\ln(1 - Pr/W) / \ln(1 + r)\), where \(P\) is the starting corpus, \(W\) is the periodic withdrawal, \(r\) is the periodic return, and \(n\) is the number of periods. This applies only when \(W > Pr\). If \(W \leq Pr\), the returns cover the withdrawal and the corpus never runs out. For example, $100,000 at 8% a year (\(r = 0.08/12\)) with $1,000 withdrawn monthly gives \(n \approx 165.3\) months, or about 13.8 years. A $500,000 corpus at 6% earns $2,500 a month, so a monthly withdrawal of $2,500 or less leaves it intact.

How does SWP differ from a Systematic Investment Plan (SIP)?

SIP puts money into a fund on a schedule, and SWP takes money out on a schedule. A Systematic Investment Plan (SIP) invests a fixed amount regularly, which builds a corpus and averages your purchase price over time. An SWP draws a fixed amount from an existing corpus, so it suits the retirement phase. Some investors run both at once, for example by continuing a small SIP in a growth fund while drawing an SWP from a debt or balanced fund.

Is SWP income tax-efficient compared to other income sources?

Often yes, because each SWP payment is a partial redemption, so only the gain inside the withdrawal is taxed, not the whole amount. For example, if a $1,000 withdrawal comes from units with a cost of $600, the taxable gain is $400. In India, for FY 2026-27 (rates in force since 23 July 2024), gains on equity-oriented funds held 12 months or more are taxed at 12.5% above Rs 1.25 lakh a year, and shorter holdings are taxed at 20%. Debt-oriented funds with less than 35% in equity bought after 1 April 2023 are taxed at your slab rate. Rules differ by country and change often, so confirm with the tax authority or a qualified tax advisor.

What is a Systematic Withdrawal Plan (SWP) and how does it work?

A Systematic Withdrawal Plan (SWP) pays you a fixed amount from a mutual fund or portfolio at regular intervals while the rest stays invested. Each period the fund redeems enough units to pay you, and the remaining balance keeps earning returns. If returns exceed the withdrawals, the corpus grows. If withdrawals exceed returns, it shrinks over time. People use SWP for retirement income because it gives predictable cash flow, and it can be more tax-efficient than interest or annuity income in some countries. Check your own jurisdiction's rules.

What is the safe withdrawal rate for long-term retirement planning?

A common starting point is 4% of the initial portfolio in year one, then raising the amount with inflation each year. The idea comes from William Bengen's 1994 research and the 1998 Trinity Study by Cooley, Hubbard, and Walz, which tested US stock and bond mixes over rolling 30-year periods and found that 4% held up in most of them. A later re-creation on 1926 to 2014 US data for a 50/50 portfolio found success rates of about 68% at 5% and 43% at 6%. For retirements of 35 to 40 years, many planners suggest 3% to 3.5%. These figures come from US history only and are not guarantees, so use them as a benchmark for the calculator, not as a promise.

What mathematical formula does the SWP calculator use?

The calculator applies the balance recursion \(B_n = B_{n-1}(1 + r) - W\), where \(B_n\) is the balance after the \(n\)-th withdrawal, \(r\) is the periodic return (annual rate divided by 12 for monthly), and \(W\) is the withdrawal. Its closed form is \(B_n = B_0(1+r)^n - W\,[(1+r)^n - 1]/r\). Setting \(B_n = 0\) and solving for \(n\) gives the depletion formula. For inflation-indexed withdrawals, \(W\) grows each year by the inflation factor: \(W_{year+1} = W_{year}(1 + i)\). The model assumes end-of-period withdrawals and a constant return, with no taxes, fees, or exit loads.

What return rate should I use in my SWP projections?

Use a rate below the long-run average, and test several. US large-cap stocks have returned roughly 10% a year in nominal terms since 1926, but single decades ranged from deep losses to very strong gains, and returns in other markets have been lower. Hybrid and debt funds usually return less and depend on interest rates in your market. Many planners use 6% to 8% for a mixed portfolio, then check the plan again at a lower rate. The order of returns matters as well: poor returns in the first years of withdrawals deplete the corpus faster than the same returns later, even when the long-run average is identical.

Why is inflation adjustment critical in SWP planning?

Inflation shrinks what a fixed withdrawal can buy. At 3% a year, $2,000 a month keeps the purchasing power of about $1,488 after 10 years and $1,107 after 20 years. To keep your real income level, the withdrawal itself has to rise: after 20 years at 3%, you need about $3,612 a month to buy what $2,000 buys today (\(2000 \times 1.03^{20}\)). An inflation-indexed plan needs a larger starting corpus or a higher return to last, which is why it is safer to assume lower returns when you index withdrawals.
Disclaimer: This calculator is designed to provide helpful estimates for informational purposes. While we strive for accuracy, financial (or medical) results can vary based on local laws and individual circumstances. We recommend consulting with a professional advisor for critical decisions.