A defined-benefit pension usually gives you two ways to take the money: a single lump sum paid the day you retire, or a smaller monthly check that continues for the rest of your life. The choice feels close to a coin flip because the two numbers are quoted in different units — one is paid once, the other stretches across decades. This pension payout calculator converts both options into the same unit: today's dollars (present value), so you can see which one is actually worth more to you at retirement.
Slide the inputs and every figure updates instantly. You can stress-test a lower or higher discount rate, plan for a shorter or longer lifespan, and see how the recommended choice flips when you expect to live longer than the median.
How to Use
- Enter the Lump Sum Offered — the one-time cash payout your plan administrator quoted. This is money you receive on day one.
- Enter the Lifetime Monthly Annuity — the guaranteed monthly check you would receive if you choose the annuity instead. It is usually quoted as a single-life amount; if your plan offers a 50% or 75% survivor option, enter the amount that would actually reach you.
- Set the Discount / Investment Return. This is the rate at which you convert future monthly payments into today's dollars. A low-risk bond yield (3%–5%) is the honest rate for valuing a guaranteed annuity; using a 7%–10% stock-return number is a common mistake that makes the annuity look worse than it really is.
- Set the Expected Years of Collection. A 65-year-old male in the United States has a Social-Security-adminised median of roughly 17–19 years of remaining life; planning to age 90 is the conservative choice and is the 25-year default used here.
- Read the result card: Lump Sum Value Today, Annuity Value Today, the PV Gap between them, the Monthly Income the Lump Sum Could Sustain over your chosen horizon, the Breakeven Months until undiscounted annuity checks equal the lump sum, and the Recommended Option.
The key number is the PV Gap. If the annuity's present value exceeds the lump sum by tens of thousands of dollars, the plan is offering you a fairly priced — often generous — lifetime income stream. If the lump sum is worth more in today's dollars, taking the cash and managing it yourself may be the better economic choice, provided you have the discipline and the low-cost portfolio to draw it down.
The Present Value of an Annuity
The math behind this calculator is the standard present-value formula for an ordinary annuity — the same equation used by actuaries, pension plans, and the numpy-financial library:
PV = PMT × (1 − (1 + r)⁻ⁿ) / r
Where:
- PMT is the monthly annuity payment.
- r is the monthly discount rate — your annual discount rate divided by 12.
- n is the total number of monthly payments — your expected collection years times 12.
Worked example on the default case: a $500,000 lump sum versus a $3,000 monthly annuity, a 4% annual discount rate, and 25 years of collection. The monthly rate is 0.04 / 12 = 0.003333, and n = 300. Plugging in gives an annuity present value of about $568,357 — roughly $68,000 more than the $500,000 lump sum in today's dollars. The same $500,000, invested at 4% and drawn down evenly over 25 years, sustains only about $2,639 per month — meaning the plan's $3,000 monthly check is buying you more income than you could safely self-manage on the same starting balance.
If the discount rate is 0%, the formula divides by zero, so the engine simply multiplies the monthly check by the number of months: $3,000 × 300 = $900,000 of undiscounted total payments.
Why the Discount Rate Is the Lever
Two people looking at the same pension offer can reach opposite conclusions just by changing the discount rate. At 3%, the $3,000 monthly check for 25 years is worth about $632,600 — the annuity wins by more than $132,000. At 6%, the same stream is worth about $463,000 — the $500,000 lump sum wins. The right rate is not the return you hope to earn on stocks; it is the return a guaranteed, low-risk stream of comparable maturity would earn today, usually a high-grade corporate or Treasury yield. Treat 7% as an aggressive upper bound on what this annuity is worth, not the central case.
Examples
Example 1 — The default 65-year-old male. A retiree is offered $500,000 today or $3,000 per month for life. Using a 4% discount rate and 25 years of expected collection, the annuity's present value is about $568,357 versus the $500,000 lump sum. The PV gap is +$68,357 in favor of the annuity, the lump sum could self-generate about $2,639 per month, and the undiscounted breakeven is around 167 months (13.9 years). If he lives past roughly age 79, the annuity pulls ahead in real dollars; past 90, it is worth far more than the lump sum ever could be.
Example 2 — A large pension, conservative draw. A public-school teacher is offered a $2,000,000 lump sum or $10,000 per month for life. She expects to live 30 years into retirement and uses a 5% discount rate. The annuity's PV is about $1,862,816 — slightly less than the $2,000,000 lump sum. The PV gap is −$137,184 in favor of the lump sum, and the lump sum could sustain about $10,736 per month over 30 years at 5%. The undiscounted breakeven is 200 months (16.7 years). The calculator flags the lump sum as the winner on economics, even though the annuity is guaranteed — a reminder that the decision is not only about money.
Example 3 — Early retirement with a long horizon. A 55-year-old is offered a $400,000 lump sum or $2,000 per month for life. Because she expects to collect for 35 years, the annuity's PV at 4% balloons to roughly $494,000 — the annuity wins by about $94,000, and the breakeven stretches to 200 months. The longer your expected collection period, the more valuable the lifetime check becomes.
FAQ
Should I take my pension as a lump sum or monthly annuity?
There is no universal answer. Convert both options to present value at a low-risk discount rate (3%–5%): if the annuity's PV exceeds the lump sum by a meaningful margin, the lifetime check is the fairer economic choice. If the lump sum wins, taking the cash and investing it in a low-cost diversified portfolio is defensible — but only if you have the discipline to draw it down slowly and the stomach to ride out market downturns without selling depressed assets.
What discount rate should I use to value a pension annuity?
Use a rate close to the yield you could earn on a guaranteed, low-risk stream of comparable maturity — typically high-grade corporate or Treasury bonds, roughly 3%–5% in today's environment. Using a 7%–10% stock-return rate overstates the risk of the annuity and makes it look worse than it is. Treat 7% as a stress-test ceiling, not your central case.
How many years should I plan to collect?
A 65-year-old male in the U.S. has a median remaining life of about 17–19 years; a 65-year-old female, about 20–22 years. The annuity pays off the longer you live, so planning conservatively (to age 90, or 25 years) is the standard choice. Run the calculator at both your actuarial expectation and age 90 — if the annuity wins at both, the decision is easy; if it only wins at age 90, longevity risk is doing the work.
What is the breakeven age on my pension lump sum?
The undiscounted breakeven is the lump sum divided by the monthly annuity, converted to years. For a $500,000 lump sum versus a $3,000 monthly check, breakeven is 167 months, or about 13.9 years — you need to live to roughly age 79 (from 65) before the annuity has paid out as much as the lump sum would have. Anything beyond that is "profit" from the annuity.
Can a lump sum actually sustain a higher monthly income than the annuity?
Sometimes. On a $500,000 lump sum invested at 4% over 25 years, the safe monthly draw is about $2,639 — below the $3,000 annuity. On a $2,000,000 lump sum at 5% over 30 years, the safe draw is about $10,736 — above a $10,000 annuity. The calculator shows both numbers so you can see whether the plan's lifetime check is generous or stingy relative to what the cash could self-generate.
What happens to my pension if I die early?
That depends on the option you choose. A single-life annuity stops at your death and the plan keeps the remaining value — which is why lump-sum advocates prefer the cash. A lump-sum balance you own becomes part of your estate and can pass to a spouse or heirs. If survivor protection matters, look at the plan's joint-and-survivor annuity options and re-run the calculator using the actual monthly payment your spouse would keep.
Disclaimer
This pension payout calculator is provided for informational purposes only and does not constitute financial, investment, tax, or legal advice. Present-value figures are based on the discount rate, expected collection years, and payment amounts you enter; actual pension terms are governed by your plan's Summary Plan Description and by IRS and PBGC rules. Life-expectancy figures are population medians and not medical forecasts for any individual. Always have a fee-only fiduciary advisor and your plan administrator review your specific election before you commit, because pension payout decisions are usually irrevocable once the first check is issued.