Retirement Calculator With Pension and Social Security Income

Only 14% of private-sector workers had access to a defined benefit pension in 2025. By comparison, 70% could use a 401(k)-type plan, according to the Congressional Research Service (Access to Retirement Benefits in the Private Sector: 2010–2025, 2026). If you have a pension, maybe from government work, teaching, the military or one of the few private employers that still offer one, your retirement math works differently. A retirement calculator with pension and social security income has one job. It tells you how much of your monthly spending those two checks cover, and whether your savings can pay for the rest for as long as you live.

Here's the short version. Add up your guaranteed income. Subtract it from what you spend. What's left is the gap your savings have to fill every month, possibly for 30 years or more. Then test that gap against many possible futures, not one average return.

Most calculators skip that last step.

How a retirement calculator with pension and Social Security works

Underneath the sliders and dropdowns, nearly every tool runs the same formula:

Monthly spending − (pension + Social Security) = monthly gap your savings must cover

Here's an example. The numbers are made up to show the math. They aren't a recommendation.

That gap comes to $27,960 a year. At a 3.9% starting withdrawal rate, you'd need roughly $717,000 in savings to support it.

Where does 3.9% come from? Morningstar's research puts the safe starting withdrawal rate at 3.9% for a 30-year retirement. "Safe" here means money was still left in 90% of simulated outcomes. It isn't based on an average return (Morningstar, The State of Retirement Income 2025, Dec 2025). So even that number is a probability, not a promise.

Most calculators don't work this way. They pick one growth rate and use it every year. Wyoming's state retirement goal calculator, for example, assumes 5% tax-deferred growth during retirement. You put one number in and get one number out. That's a fine starting point, but it doesn't tell you much about risk.

Why one average return isn't enough

Markets don't hand you 5% every year. They give you a good stretch, then a bad one, then something in between, and the order matters a great deal. A downturn in your first few years of withdrawals can do far more damage than the same downturn 15 years later. An average-return calculator can't show this, because in its world every year is the same.

A Monte Carlo simulation sounds technical, but the idea is simple. It runs your plan through hundreds or thousands of possible market paths: strong decades, weak decades, bad years right after you retire. Then it counts how many of those paths still have money left at the end. The result is a success rate, such as "82% of futures stay funded," not a single balance on a single date.

This matters more when you have a pension. Guaranteed income shrinks the gap, so you sell fewer investments in bad years. A good calculator should show that benefit as a higher success rate, not just a smaller number.

Five pension decisions a calculator should make you face

Your pension is more than one number. These choices can change your plan more than a point or two of return assumptions.

1. Does your pension keep up with inflation?

Many calculators treat this as a yes/no toggle. Western & Southern's tool, for example, asks whether your pension rises with inflation and defaults to "No." Real pensions are messier. Some have no cost-of-living adjustment (COLA). Some have a partial one. Some cap it.

The cost of a fixed pension adds up quietly. Suppose inflation runs at 3% a year, which is just an assumption to show the math. After 25 years, a fixed $1,500 pension buys roughly what about $720 buys today. Your check stays the same, but it covers less and less, so your gap grows every year. Check your plan documents for the exact COLA terms.

Social Security, by contrast, gets an annual COLA. For 2027 it's 3.6% (more on that below).

2. Lump sum or monthly payments?

Some plans let you take a lump sum in place of lifetime payments. A lump sum gives you control and something you can leave to heirs. It also moves market risk and longevity risk off the pension plan and onto you. Monthly payments do the opposite. For your calculator, the decision changes which column the money goes in: guaranteed income or savings.

3. Single-life or joint-and-survivor?

A single-life payout pays more each month but stops when you die. A joint-and-survivor option pays less but keeps going for your spouse. For couples this matters a lot. When one spouse dies, the household usually loses one of its two Social Security checks. If the pension stops too, the survivor's income can drop sharply while many expenses stay about the same. A calculator built for households should let you model both spouses, as some bank tools try to do with spouse pensions and a non-working spouse's benefit.

4. When does each check start?

Your pension might start at 60. You might wait until 67 or 70 to claim Social Security. In the years between, your savings carry more of the load. So your gap isn't one fixed number. It's large early on and shrinks later. A calculator that treats all your income as starting the day you retire will overstate your odds.

5. What about taxes?

Pension income is generally taxable, and part of your Social Security can be taxed too, depending on your other income. Higher income can also raise your Medicare premiums through income-based surcharges. Net income is what you actually spend, so plan with after-tax numbers where you can.

Social Security numbers to plug in for 2027

If your calculator's Social Security figures are a year old, update them.

• The 2027 COLA is 3.6%. It affects about 76 million Social Security and SSI recipients (Social Security Administration, announcement, October 2026). It's the largest increase since 2023 (CNBC, October 2026).
• The average retirement benefit rises to about $2,170 a month in January 2027, up from $2,095 before the COLA (Kiplinger).

Averages are only a placeholder. Use your own estimate from your Social Security statement, and check it at the age you actually plan to claim.

Public-sector workers: WEP and GPO are gone

This is where many ranking calculators and articles are out of date. Some still say a non-covered government pension can cut your Social Security. That stopped being true.

The Social Security Fairness Act, signed January 5, 2025, repealed both the Windfall Elimination Provision (WEP) and the Government Pension Offset (GPO). The repeal applies to benefits for months after December 2023, and affected beneficiaries received back pay for 2024 (ASPPA; NAPA).

What this means for your plan:

• If a tool asks whether your pension came from non-covered work and then reduces your Social Security, it's using old rules.
• Teachers, police, firefighters and other public workers who once had reduced or no spousal or survivor benefits should rerun their numbers using their current SSA estimate.
• Many public workers were never affected. About 72% of state and local government workers are in jobs covered by Social Security (Mercer Advisors).

Plan for a long life and real health care costs

Two more numbers belong in any plan, with or without a pension.

Longevity. About one in three 65-year-olds may live to at least 90, according to Social Security's planning guidance (SSA, Retirement Information for Medicare Beneficiaries, 2026). A plan that ends at 85 quietly bets against a third of retirees. A lifetime pension helps here, but your savings still have to last as long as you do.

Health care. Fidelity estimates a 65-year-old retiring this year will spend $172,500 on Medicare premiums, deductibles and prescriptions over retirement, and that figure leaves out long-term care entirely (Fidelity Investments, 2025 Retiree Health Care Cost Estimate, Jul 2025). That isn't a rounding error. It belongs in your monthly spending.

And if you've never worked out your monthly number, you're not alone. EBRI's 2025 Retirement Confidence Survey found only 52% of workers have estimated the monthly income they'll need in retirement (EBRI/Greenwald, Retirement Confidence Survey 2025, Fact Sheet 3).

Run your own numbers

Here's a checklist before you trust any calculator's answer:

1. Monthly spending, including health care.
2. Your Social Security estimate at your planned claiming age, using current rules.
3. Your pension amount, its COLA terms, its start date and your survivor option.
4. A plan horizon that runs past 90.
5. A result shown as a probability across many futures, not one projected balance.

Monte Climb is built around that last point. You enter three numbers: your age, what you've saved and what you spend each month. We run them through 1,000 simulated futures and show what share stay funded. It runs in your browser, and nothing is saved until you say so. Plans run to age 95 by default, and the engine charges Medicare premiums and income-based surcharges year by year rather than using a flat guess.

One honest note: that quick calculator asks for spending, not for each income source. For a rough first look, you can think of your number as the gap your savings need to fill. Just remember that shortcut assumes your pension and Social Security start right away and keep pace with inflation. If yours don't, your real odds may be lower. From there, you can ask William, our AI planner, follow-up questions like "Am I on track?", "Can I retire at 62?" or "What's a sustainable spend?" He shows his work.

It's planning software, not advice. It gives you a probability, not a promise. But it's a much clearer place to start than a single average.

Show my answer → Three numbers. One clear answer. A 7-day trial is available for $1.

Frequently asked questions

How do I calculate retirement income with a pension and Social Security?

Add your monthly pension and Social Security benefit, then subtract that total from your expected monthly spending. The difference is the gap your savings must cover. Then test whether your savings can sustain that gap across many possible market outcomes, not just one average return.

Does a pension reduce Social Security benefits anymore?

Not because of WEP or GPO. The Social Security Fairness Act, signed January 5, 2025, repealed both for benefits payable for months after December 2023. Calculators that still cut your Social Security for a non-covered pension are using outdated rules.

What is the Social Security COLA for 2027?

The Social Security Administration announced a 3.6% cost-of-living adjustment for 2027 in October 2026. It affects about 76 million Social Security and SSI recipients. Kiplinger estimates the average retirement benefit will rise to about $2,170 a month.

Should my retirement calculator assume my pension rises with inflation?

Only if your plan actually has a cost-of-living adjustment. Many pensions are fixed or have partial or capped COLAs. At an assumed 3% inflation rate, a fixed pension loses roughly half its buying power over 25 years, which widens the gap your savings must fill.

Why use a Monte Carlo retirement calculator instead of a standard one?

Standard calculators apply one fixed return every year and give one answer. A Monte Carlo calculator runs your plan through many simulated market paths, including bad years early in retirement, and reports the share that stay funded. That gives you a probability of success instead of a single projection.