Pension Lump Sum vs Monthly Payments Calculator

• Finds the implied annual return the monthly pension pays on the lump sum, for the ages you expect to live to.
• Values the pension at your own discount rate and shows simple and discounted break-even ages.
• Handles cost-of-living increases and joint-and-survivor options that keep paying a spouse.
• Shows the 20% mandatory withholding and the 10% early-withdrawal tax if you take cash instead of rolling over, with the age-55 exception.

How to use this calculator

Enter the lump sum and the monthly pension from your plan's election paperwork, your age when payments would start, the age you want to plan to, and a discount rate. Open Advanced to add a cost-of-living increase, choose a joint-and-survivor option with your spouse's ages, set the return you would expect on the invested lump sum, or see the cost of taking the lump sum in cash.

If you choose a survivor option, enter the reduced monthly amount the plan quotes for that option, not the single-life amount. Try several life expectancies: the answer can flip between them.

The implied rate of return

Taking the monthly pension is like handing the plan your lump sum and receiving an income for life in return. The implied return is the interest rate at which the payments you expect to receive are worth exactly the lump sum today. If it is higher than the return you could safely earn yourself, the pension is the better deal on those assumptions; if it is lower, the lump sum is.

It is a guaranteed return, which matters. Matching it with investments means taking market risk, and the pension also insures you against living longer than expected, something a pot of money cannot do.

How the calculator works

Pension payments  = monthly amount, rising once a year by any COLA,
                    from now until your planning age
                    (+ survivor % to your spouse until their planning age)
Present value     = sum of payments / (1 + discount rate)^(time)
Implied return    = the rate at which present value = lump sum
Simple break-even = age when total payments reach the lump sum
Drawdown          = invest the lump sum, withdraw the pension amounts monthly
Cash-out          = lump sum - income tax - 10% additional tax (under 59 1/2, no exception)

Payments are treated as made at the start of each month. Lives last exactly to the ages entered; there is no mortality table, so try more than one age.

A worked example

With the calculator's starting values, a 62-year-old is offered $375,000 or $2,400 a month for life, with no cost-of-living increase. If they live to 85, the pension pays $662,400 in total and its implied return is 5.71% a year. Valued at a 5% discount rate it is worth $398,914, $23,914 more than the lump sum. Total payments catch up with the lump sum at age 75.1, or 82.7 once the payments are discounted at 5%.

Planning to 90 instead raises the implied return to 6.64%; planning to 78 lowers it to 2.72%. That range is the heart of the decision.

A married retiree offered $2,200 a month as a joint and 50% survivor pension, with a spouse aged 60 expected to live to 88, gets an implied return of 5.27%, because payments continue to the spouse.

Rolling over versus cashing out

If you take the lump sum, you can have the plan send it straight to an IRA in a direct rollover. Nothing is withheld and no tax is due until you withdraw. If the plan pays the money to you instead, it must withhold 20% for federal income tax, even if you intend to roll it over yourself within 60 days. To roll over the full amount you would then have to find the withheld 20% from other money.

A taxable lump sum taken before age 59½ also faces a 10% additional tax unless an exception applies. One important exception for employer plans is leaving the job in or after the calendar year you turn 55 (50 for qualified public safety employees in government plans). Monthly pension payments are not subject to the 10% additional tax once you have separated from service. Rolling the lump sum into an IRA ends the age-55 exception for that money, so withdrawals from the IRA before 59½ would usually face the 10% tax.

For example, a 52-year-old who takes the $375,000 in cash, with no exception and a combined 24% tax rate, has $75,000 withheld, pays $37,500 of additional tax, and keeps about $247,500.

Why interest rates change the lump sum

Plans do not choose lump sums freely. Under section 417(e) of the tax code, the lump sum must be at least the present value of your pension using IRS interest rates, known as the minimum present value segment rates, and an IRS mortality table. For June 2026 the three segment rates were 4.49%, 5.43% and 6.18% (IRS Notice 2026-44). When these rates rise, lump sums shrink; when they fall, lump sums grow. Plans usually fix the rates from a 'lookback' month, so the same pension can produce a noticeably different lump sum from one plan year to the next.

Assumptions and limitations

• Fixed lifespans. The calculator uses the ages you enter rather than probabilities of survival.
• Taxes. With a rollover, tax is ignored because both choices are taxed as ordinary income when received. With a cash-out, the same flat rate is applied to the lump sum and to the pension payments; a large lump sum can push you into a higher bracket.
• Steady returns. The drawdown uses one return every year. Real markets vary, and poor returns early in retirement do lasting damage.
• Guarantees. Most private pensions are insured by the PBGC up to legal limits; government plans are not. The plan's financial health is not assessed.
• Other benefits. Retiree health coverage or other benefits tied to taking the annuity are not included.

Common mistakes

Comparing the lump sum with a few years of payments. The pension pays for life, so the comparison has to run to a realistic age.

Assuming you will beat the implied return. Matching it means taking market risk with money that has to last for life.

Taking a check instead of a direct rollover. The 20% withholding and a possible 10% additional tax can cost tens of thousands of dollars.

Choosing single life without considering a spouse. A single-life pension stops at your death. A married participant normally needs the spouse's written consent to give up the survivor benefit.

Ignoring inflation. Without a cost-of-living increase, a fixed pension buys less every year.

Frequently asked questions