Lifetime Annuity Calculator: Estimate Income and Longevity Outcomes
Use this guide to understand the assumptions, inputs, results, and next steps behind the calculator.
Created by Luis Gonzalez · Last updated July 4, 2026
A lifetime annuity exchanges a lump sum for a stream of income, often for as long as the annuitant lives. This calculator estimates the income from a purchase amount and payout rate, increases payments by an assumed annual percentage, and totals payments through a selected life expectancy. It also estimates an internal rate of return (IRR), which is the discount rate that makes the projected payments equal the purchase price.
With the default inputs—$300,000 purchased at age 62, a 5.8% payout rate, and 2% annual increases—the estimated first-year income is $17,400, or $1,450 per month. Over 28 payout years through age 90, modeled total payouts are $644,691. The final-year annual income is $29,700, and the estimated IRR is 5.6%.
These are illustrative cash-flow estimates, not an insurer quote or a guarantee of product terms. A real contract may include different payment timing, survivor benefits, refund features, fees, and tax treatment. Compare the retirement annuity calculator and immediate annuity calculator for related estimates.
Set the purchase, payout, and planning assumptions
Enter the purchase amount, age at purchase, payout rate, annual increase, and life expectancy. The payout rate determines the first year’s income as a percentage of the premium. The annual increase compounds payment growth each year.
Inflation is used to estimate the purchasing power of future payments. Tax rate and alternative return are shown among the inputs, but neither is used in the provided computation of the result cards. The model’s IRR is calculated from gross annual payments and purchase amount; it does not subtract taxes or compare against the alternative return input.
For household planning, estimate other guaranteed income and expenses separately. A retirement income estimate or retirement needs calculation can show how annuity income fits with other resources. Consider health costs using the Medicare lifetime cost calculator.
Read total payouts together with longevity risk
The total payout is the sum of modeled payments, not a measure of investment profit. It does not account for the timing and purchasing power of each payment. Receiving $300,000 in nominal payments over many years is not equivalent to receiving $300,000 today.
The default result’s $644,691 total is based on 28 payments, starting with $17,400 in the first year and increasing by 2% annually. The last payment is $29,700. After 2.5% inflation, the model estimates the final-year payment has purchasing power of $14,876 in the calculation’s real-income measure. The nominal payment rises while its purchasing power can still fall if inflation outpaces the payment increase.
Longevity changes the outcome materially. At the default assumptions, the calculator’s longevity table estimates total payments of $255,438 if life expectancy is 75, compared with $976,400 if it is 100. The former is 15 years of payouts; the latter is 38 years. Those totals do not mean the annuity is necessarily a loss or gain in economic value: the contract’s value includes the insurance against living longer than expected.
| Life expectancy scenario | Payout years from age 62 | Estimated total payouts | Estimated return vs. premium |
|---|---|---|---|
| 75 | 13 | $255,438 | -15% |
| 80 | 18 | $354,035 | 18% |
| 85 | 23 | $464,201 | 55% |
| 100 | 38 | $976,400 | 225% |
The calculator’s longevity table reports return as total payouts minus purchase amount, divided by purchase amount. It is not annualized IRR. The IRR card instead estimates an annualized rate from the sequence and timing of cash flows.
Compare increasing payments with inflation protection
An increasing-payment feature can help offset inflation, but the starting payment may be lower than a level-payment option with otherwise similar terms. Here, payments grow by 2% per year while assumed inflation is 2.5%; that means the real value of payments trends downward under the model’s assumptions.
Changing the annual increase can affect both first-year purchasing power and lifetime payouts. Ask the insurer for contract-specific quotes using the same purchase amount, age, payout form, and survivor options. Compare the cost of inflation protection with the value of having a higher initial income.
Also check whether the quote is single-life or joint-life. A joint-life option may continue payments to a surviving spouse but can reduce the initial payment. A period-certain or cash-refund feature may protect beneficiaries if death occurs early, but it can also change the income amount. The generic calculator does not model those contract options.
The annuity calculator and investment annuity calculator can support broader comparisons. If you are evaluating retirement cash-flow alternatives, compare a 4% withdrawal approach or a bucket strategy as well.
Formulas used for the projection
The calculator uses a fixed first-year payout, compounds it by the annual increase, sums each annual payment, and solves for an IRR from the resulting cash-flow sequence.
First-year annual income =
purchase amount × payout rate
= $300,000 × 5.8%
= $17,400
Monthly income =
first-year annual income / 12
= $17,400 / 12
= $1,450
Annual income in payout year =
first-year income × (1 + annual increase) ^ (year - 1)
Age 90 payment = $17,400 × (1.02 ^ 27)
= $29,700 (rounded)
Total payouts =
sum of each annual payment from year 1 through year 28
= $17,400 + $17,748 + ... + final-year payment
= $644,691 (rounded)
The IRR solves for the annual rate that discounts every projected payment back to the $300,000 purchase amount. Because the calculator rounds the reported IRR to one decimal place, 5.6% is an estimate rather than a precise quoted yield.
Tax treatment and insurer protections
Annuity payments may be partly taxable depending on how the contract was funded and the applicable tax rules. Qualified annuity payments are generally taxed differently from payments on a nonqualified contract, where part of each payment may represent a return of basis. The calculator’s 22% tax-rate input does not change its output, so do not treat the displayed income as after-tax income.
The IRS guidance on annuities explains general rules for distributions. Tax treatment depends on contract and account details. If the annuity is held in an IRA or employer plan, required minimum distribution rules may also apply; see the IRS explanation of RMDs.
Annuity guarantees depend on the insurer’s claims-paying ability. State guaranty associations have limits and rules that vary by state, and they are not a substitute for evaluating the insurer’s financial strength. Check contract terms, surrender charges, free-look rights, and any state disclosures before purchasing.
Questions about lifetime annuities
Does a 5.6% IRR mean the annuity earns 5.6% every year?
No. The IRR is the annualized rate implied by the modeled purchase and payment cash flows if the assumed payments occur. It does not guarantee investment growth or show the contract’s terms under every outcome.
What happens if I die before the assumed life expectancy?
The result depends on the contract. A single-life annuity may stop at death, while joint-life, refund, or period-certain options may continue payments. The calculator does not include those provisions, so request the exact contract payout form.
Should I buy at 62 or wait?
Buying later usually changes the payout rate because the insurer expects payments to last for fewer years, but the actual quote depends on rates, product design, and personal options. Waiting also means giving up income during the delay and keeping the purchase money exposed to market and spending risks. Compare quotes at each age using identical features.
Is the total payout the same as the annuity’s value?
No. Total payouts add nominal dollars without discounting them for timing, inflation, or investment alternatives. The IRR and payment guarantee provide different information, and neither alone captures every benefit or risk.
Is the displayed monthly income after tax?
No. It is the gross first-year payment divided by 12. The tax-rate input is not applied to the result in the provided calculation.
Does the calculator account for inflation automatically?
It calculates a real-income estimate using the inflation input, but it does not subtract inflation-adjusted dollars from the nominal total-payout figure. A 2% payment increase with 2.5% inflation does not fully preserve purchasing power.
Next steps: compare actual contracts
Ask insurers for side-by-side quotes for single-life and joint-life coverage, level and increasing payments, and any refund or period-certain options you may want. Compare the initial monthly income, survivor benefit, payout guarantees, fees, and insurer strength—not just the total payout estimate.
Before committing, test how much of essential spending is covered by Social Security, pensions, and other guaranteed income. Consider a deferred income annuity for later-life income, an IRA annuity estimate if using retirement-account assets, and a retirement withdrawal strategy for the assets you do not annuitize.