Immediate Annuity Calculator (SPIA) — Estimate Lifetime Monthly Income

A single-premium immediate annuity (SPIA) is an insurance contract where you pay one lump sum and, in return, the insurer sends you a guaranteed income stream that starts within a year — usually within a month — and continues for life. It is the mirror image of a deferred annuity, which has a growth phase first; for deferred fixed annuities with surrender charges and guaranteed accumulation rates, see our deferred fixed annuity calculator.

It prices your premium the way insurers do: with a life annuity factor built from a mortality table plus an interest rate. We use the U.S. Social Security Administration 2023 period life table (2026 Trustees Report) for survival probabilities by age and sex, then discount each expected future monthly payment at the annual rate you enter. Example: $100,000 at age 65, male, 5% pricing rate, life-only gives about $740.20 per month. This is an estimate, not an annuity quote and not professional advice.

Our annuity calculator amortizes a lump sum over a fixed number of years that you choose — pure time-value-of-money math with no mortality involved. This immediate annuity calculator is product-specific: it estimates lifetime income using your age and sex via a mortality table, and supports SPIA payout options (life-only, life with period certain, joint and survivor). Rule of thumb: payments for a fixed term only → use the annuity calculator; income for life → use this one.

Because women live longer on average, so the same premium must stretch over more expected payments. From the Social Security life table, a 65-year-old woman has about 20.7 years of remaining life expectancy versus about 18.2 for a 65-year-old man. At $100,000, 5%, life-only: about $676.87 per month for a 65-year-old woman versus about $740.20 for a 65-year-old man — same math, longer payout horizon.

Life-only pays the highest monthly amount but stops completely when you die — if you die early, the insurer keeps the remainder. Life with period certain (for example 10 or 20 years) guarantees payments for at least that long: if you die during the guarantee period, your beneficiary receives the remaining payments. The guarantee costs you monthly income — for a 65-year-old man at 5%, life with 10-year certain pays about $698.07 per month versus about $740.20 life-only.

It covers two lives — typically spouses — and keeps paying as long as either person is alive. You choose what fraction continues after the first death: 100%, 75%, or 50% of the original payment. Covering two lives costs income: $100,000 for a 65-year-old man with a 65-year-old wife at 5% pays about $596.50 per month with 100% survivor benefit, versus about $707.12 with 50% survivor benefit and about $740.20 for his life only.

The age at which your cumulative payments equal the premium you paid — after that, every check is effectively profit funded by mortality credits from annuitants who died earlier. For $100,000 at 65 (male, 5%, life-only, about $740.20 per month), the break-even age is about 76.3. Living past break-even is the longevity insurance paying off; dying before it means the insurer kept the difference.

The pricing rate is the insurer's assumed investment return, and a higher rate means a higher payout: $100,000 at 65 (male, life-only) pays about $680.47 per month at 4% versus about $740.20 at 5% and about $863.34 at 7%. Insurers price conservatively and add expenses, profit margins, and commissions, so real quotes are usually lower than a raw table-plus-rate estimate. Compare quotes from at least three insurers.

No. This tool gives an educational estimate from public mortality data and a rate you choose — it is not an annuity quote, not a solicitation, and not professional financial advice. Real insurer quotes use annuitant mortality tables (annuity buyers live longer than the general population), the insurer's own interest assumptions, state premium taxes, agent commissions, and rider costs. Talk to a licensed professional before buying.

With life-only, payments stop at death and the insurer keeps any unrecovered premium — those forfeited funds (mortality credits) are exactly what lets the insurer pay above-market income to people who live very long. If leaving money behind matters, choose life with period certain or a cash-refund option instead; both guarantee your premium (or the payments) go to a beneficiary, at the cost of a lower monthly check.

There is no single right answer, but the math is clear: the older you are at purchase, the higher the monthly payout, because your life expectancy is shorter. At $100,000, 5%, life-only, male: about $740.20 per month at 65, about $1,013.46 at 75, and about $1,270.16 at 80. Waiting raises income but means fewer years of payments and more years funding retirement some other way.

The U.S. Social Security Administration Period Life Table for 2023, as used in the 2026 Trustees Report (table 4c6): the probability of dying within one year and the number of survivors at each exact age, for men and women. It describes the general U.S. population — annuity buyers tend to live longer, which is one reason insurer quotes differ from this estimate. Monthly survival between birthdays is interpolated assuming deaths spread evenly within each year of age (uniform distribution of deaths).