How long will my retirement savings last with regular withdrawals?

The payout duration depends on your lump sum amount, the withdrawal amount, and the expected return rate. A larger lump sum, lower withdrawal amount, or higher return rate extends how long the money lasts. Use the calculator to find a sustainable withdrawal rate for your retirement horizon.

How does inflation affect my fixed annuity payouts?

Fixed payouts lose purchasing power over time due to inflation. At 3% annual inflation, a ,000 monthly payment will buy only about ,490 worth of goods after 10 years. Consider inflation-adjusted annuities or variable payout strategies for long-term retirement income.

What happens to annuity payments if I die before the payout period ends?

Some annuities include a period certain feature that guarantees payments to your beneficiaries for the remainder of the term. Others stop at death. Check your contract for survivor benefits or consider a joint-life annuity for spousal protection.

What is the difference between a fixed period payout and a lifetime annuity?

A fixed period payout guarantees payments for a specific number of years regardless of lifespan. A lifetime annuity pays as long as you live but may stop earlier if you die before recovering your premium. This calculator models fixed period payouts.

Annuity Payout Calculator

Calculation Mode

Principal Amount ($)

Annual Interest Rate (%)

Compounding Frequency

Withdrawal per Period ($)

Introduction

An annuity payout calculator is an essential retirement planning tool that determines how much income you can receive from a lump sum of money over a fixed period. This is the reverse of the standard annuity calculation: instead of calculating the future value of regular contributions, this calculator determines the periodic payment amount that a given lump sum can provide, considering a specific interest rate and payout duration.

This calculation is critical for anyone approaching retirement who needs to convert savings into reliable income. Whether you have a 401(k), IRA, pension lump sum, or business sale proceeds, knowing your safe monthly withdrawal amount is fundamental to retirement planning.

The annuity payout calculation is the foundation of annuitization, converting a lump sum into guaranteed payments. Insurance companies use these same formulas for fixed immediate and deferred annuities. Understanding the math helps you evaluate whether buying an annuity is worthwhile compared to systematic withdrawals.

The calculator supports several important variations. You can calculate the payment amount for a fixed number of periods, sometimes called a period certain annuity. You can also determine how long a lump sum will last given a specific withdrawal amount, which is essential for determining whether your savings will last through retirement. For those considering lifetime annuities, the calculator can also show how the payment amount changes when you factor in life expectancy.

The payout calculation also supports withdrawal rate planning. The famous 4% rule suggests that withdrawing 4% of your initial portfolio annually, adjusted for inflation, is safe for a 30-year retirement. This calculator tells you exactly how much you can withdraw per period under different assumptions.

Understanding the relationship between lump sum, withdrawal amount, interest rate, and payout duration helps you make informed retirement income decisions.

How to Use

The annuity payout calculator offers several calculation modes to answer different retirement planning questions.

To calculate the periodic payout amount, start by entering the lump sum or accumulated balance you plan to annuitize. This could be your total retirement savings balance, the proceeds from a pension buyout, or the premium you plan to pay for an immediate annuity contract.

Enter the expected annual rate of return or interest rate. For conservative planning, use a rate that reflects safe investments such as high-quality bonds or CDs. Current Treasury rates provide a good benchmark for risk-free returns. For more aggressive planning, you might use a blended rate that reflects a balanced portfolio of stocks and bonds.

Specify the payout frequency. Monthly payouts are most common for retirement income, but you can also calculate quarterly, semi-annual, or annual payments depending on your needs.

Enter the number of payout periods or the desired payout duration in years. If you are planning for a 30-year retirement and want monthly payments, this would be 360 periods. The longer the payout period, the smaller each payment will be for a given lump sum.

Select whether payouts occur at the beginning or end of each period. Payments at the beginning of the period (annuity due) are slightly larger in total because each payment has one fewer period to be discounted, making this structure more favorable if you need income immediately.

If you prefer to calculate the payout duration instead, enter the desired periodic payment amount and the calculator will determine how many periods the lump sum will last. This is particularly useful for answering the question: how long will my savings last if I withdraw a specific amount each month.

Press Calculate to see your results. The calculator displays the periodic payment amount, the total amount paid out over the full period, and the total interest earned. An optional payout schedule shows the breakdown of each payment into interest and principal components, similar to an amortization schedule but in reverse. In an annuity payout, early payments contain a higher proportion of interest, while later payments consist mostly of principal return.

Formulas and Calculations

The annuity payout calculation solves for the periodic payment P given a known present value (the lump sum), a periodic interest rate, and a number of periods. This is mathematically identical to the loan payment formula.

Let us define the key variables:

PV = present value or lump sum amount
r = annual interest rate as a decimal
n = total number of payout periods
i = periodic interest rate (r divided by periods per year)

Payment for a Fixed Number of Periods (Ordinary Annuity - end of period)

P = \frac{PV \times i}{1 - (1+i)^{-n}}

This formula calculates the fixed periodic payment that exactly depletes the lump sum after n periods, assuming interest is earned on the remaining balance at rate i per period.

Payment for Annuity Due (payments at beginning of period)

P_{Due} = \frac{PV \times i}{(1 - (1+i)^{-n}) \times (1+i)}

Solving for Number of Periods Given Payment Amount

If you know how much you want to withdraw each period and want to know how long the money will last:

n = \frac{\log\left(\frac{P}{P - PV \times i}\right)}{\log(1+i)}

This formula requires that P is greater than PV × i, meaning the withdrawal exceeds the interest earned in the first period. If P is less than or equal to PV × i, the principal never decreases and the money lasts indefinitely.

Total Interest Earned

Total\;Interest = (n \times P) - PV

Example Calculation - Payout Amount

Suppose you have a $500,000 retirement nest egg and want to withdraw monthly payments over 30 years, earning 5% annually.

Given: PV = $500,000, Annual rate = 5%, so i = 0.05 / 12 = 0.004167, n = 30 × 12 = 360 months

P = \frac{500{,}000 \times 0.004167}{1 - (1.004167)^{-360}}

P = \frac{2{,}083.33}{1 - 0.2236}

P = \frac{2{,}083.33}{0.7764} = 2{,}683.19

So you could withdraw approximately $2,683 per month for 30 years before depleting the account.

Example Calculation - How Long Will It Last

Suppose you have $500,000, earn 5% annually, and want to withdraw $3,500 per month. How long will your savings last?

n = \frac{\log\left(\frac{3{,}500}{3{,}500 - 500{,}000 \times 0.004167}\right)}{\log(1.004167)}

n = \frac{\log\left(\frac{3{,}500}{3{,}500 - 2{,}083.33}\right)}{\log(1.004167)}

n = \frac{\log(2.471)}{\log(1.004167)} = \frac{0.905}{0.004158} = 217.7 \text{ months}

This is approximately 18.1 years. By withdrawing $3,500 per month instead of $2,683, you reduce the longevity of your portfolio from 30 years to about 18 years.

For more information, see the Present Value Calculator.

Reference Table

Monthly Payout for export default function AnnuityPayoutPage00,000 Lump Sum

Interest Rate	10 Years	20 Years	30 Years
3%	$966	$555	$422
4%	export default function AnnuityPayoutPage,012	$606	$477
5%	export default function AnnuityPayoutPage,061	$660	$537
6%	export default function AnnuityPayoutPage,110	$716	$600
7%	export default function AnnuityPayoutPage,161	$775	$665
8%	export default function AnnuityPayoutPage,213	$836	$734

How Long Savings Last ($500,000 Lump Sum at 5%)

Monthly Withdrawal	Years Until Depletion	Total Payout
$2,000	34.6 years	$830,400
$2,500	27.4 years	$822,000
$3,000	21.9 years	$788,400
$3,500	18.1 years	$760,200
$4,000	15.5 years	$744,000
$5,000	11.9 years	$714,000

Safe Withdrawal Rates by Retirement Duration

Duration	Safe Rate (90% Success)	Conservative Rate (99% Success)
20 years	5.5%	4.5%
25 years	4.8%	4.0%
30 years	4.0%	3.5%
35 years	3.5%	3.0%
40 years	3.0%	2.5%

Practical Tips

The withdrawal rate is the most important factor in determining how long your retirement savings will last. A difference of just 0.5% in your annual withdrawal rate can add or subtract years from your portfolio's longevity. Use the calculator to test different withdrawal scenarios before committing to a retirement income plan.

Consider using a variable withdrawal strategy rather than a fixed amount. In years when investment returns are strong, you can withdraw more. In down years, reduce withdrawals to preserve principal. This approach increases the probability that your savings will last through retirement compared to a fixed withdrawal strategy.

Delay taking Social Security benefits if possible. Each year you delay beyond your full retirement age increases your monthly benefit by approximately 8% until age 70. Delaying Social Security effectively provides cheap longevity insurance, as the increased inflation-adjusted payments continue for life.

The 4% rule is a guideline, not a guarantee. Originally based on historical US stock and bond returns, it may not be appropriate for all market environments, especially periods of low interest rates or high inflation. Use the calculator with conservative return assumptions to stress-test your retirement plan.

Consider annuitizing a portion of your savings to cover essential expenses. By purchasing a fixed immediate annuity that covers your basic living costs, you create a guaranteed income floor. The remainder of your portfolio can be invested more aggressively for growth, providing upside potential and liquidity.

Limitations

Constant Interest Rate Assumption: The annuity payout calculator assumes a constant interest rate over the entire payout period. In reality, investment returns vary significantly year to year. Sequence-of-return risk, where poor returns early in retirement deplete principal faster than expected, can cause premature portfolio depletion even if average returns meet expectations.
Inflation Not Accounted For: The calculator does not account for inflation. Fixed payments that seem adequate today may have significantly reduced purchasing power 20 or 30 years into retirement. Consider using an inflation-adjusted return rate or selecting an inflation-adjusted annuity product to maintain purchasing power over time.
Simplified Longevity Risk: Longevity risk is simplified to a fixed number of periods. In reality, you do not know exactly how long you will live. A period certain annuity that pays for exactly 30 years leaves you with no income if you live longer. Lifetime annuities have different payout calculations based on mortality tables that are not captured by this basic calculator.
Taxes Not Modeled: Taxes on retirement account withdrawals are not modeled. Withdrawals from traditional 401(k) and IRA accounts are taxed as ordinary income. The after-tax amount available for spending may be significantly lower than the pretax withdrawal amount calculated by the tool.
Fees and Expenses: Fees, management expenses, and advisory costs can meaningfully reduce the effective return on your retirement portfolio. Even a 1% annual fee reduces the sustainable withdrawal rate and shortens portfolio longevity. Factor these costs into your return assumptions.

Frequently Asked Questions

How long will my retirement savings last with regular withdrawals?: The payout duration depends on your lump sum amount, the withdrawal amount, and the expected return rate. A larger lump sum, lower withdrawal amount, or higher return rate extends how long the money lasts. Use the calculator to find a sustainable withdrawal rate for your retirement horizon.
How does inflation affect my fixed annuity payouts?: Fixed payouts lose purchasing power over time due to inflation. At 3% annual inflation, a ,000 monthly payment will buy only about ,490 worth of goods after 10 years. Consider inflation-adjusted annuities or variable payout strategies for long-term retirement income.
What happens to annuity payments if I die before the payout period ends?: Some annuities include a period certain feature that guarantees payments to your beneficiaries for the remainder of the term. Others stop at death. Check your contract for survivor benefits or consider a joint-life annuity for spousal protection.
What is the difference between a fixed period payout and a lifetime annuity?: A fixed period payout guarantees payments for a specific number of years regardless of lifespan. A lifetime annuity pays as long as you live but may stop earlier if you die before recovering your premium. This calculator models fixed period payouts.

References

Bengen, William P. "Determining Withdrawal Rates Using Historical Data." Journal of Financial Planning, 1994.
Pfau, Wade D. "Retirement Planning Guidebook." Retirement Researcher Media.
Blanchett, David. "Dynamic Withdrawal Strategies." Journal of Financial Planning.
Internal Revenue Service. "Required Minimum Distributions." IRS.gov.
Social Security Administration. "Retirement Benefits." SSA.gov.
Investopedia. "How to Calculate Annuity Payouts."
Morningstar. "Safe Withdrawal Rates for Retirement Planning."

Last updated: May 12, 2026