Retirement Planning Software Comparison: Features That Matter

38% in one tool. 84.75% in another. Same plan.

One retiree on a forum ran a single plan through four tools. FIRECalc's historical mode said 38%. FIRECalc's Monte Carlo mode said 55.5%. Vanguard said 57%. Portfolio Visualizer said 84.75% (early-retirement.org). It's one person's report, not a controlled study. Still, it shows something most retirement planning software comparisons leave out: the tool you pick can change your answer as much as your savings can.

So here's the short answer before we go deeper. Choose a tool you can understand. You should be able to see how it simulates markets, what it assumes, how long it plans for, and what its "success rate" actually measures. Features like account linking and tax modeling come after that.

A disclosure, since most pages on this topic don't make one: we build Monte Climb, a Monte Carlo retirement planner. We'll tell you where we fit near the end. Everything before that applies to any tool, ours included.

The usual shortlist

Most people deciding on do-it-yourself retirement software end up choosing among a handful of names. Prices below come from published reviews. Reviews disagree with each other on price, so check each vendor's own pricing page before you decide.

Sources: Rob Berger, Bonsave, Marriage Kids and Money, RetirementPlanningTools.net, The College Investor, WealthFluent, Boldin.

That table tells you what a tool has. It doesn't tell you whether its answer is any good. That's the harder question.

Why the same plan gets different answers

The forum example above is anecdotal, but it matches research. A 2019 study reported by NAPA found that retirement calculators gave very different results for the same person. Investment return assumptions differed the most, especially how tools handled returns before and after retirement (NAPA, Feb 2019).

That's the clue. Most of the gap between tools comes from assumptions, and the assumptions are often the least visible part of the product.

Features that matter in a retirement planning software comparison

1. How the engine generates the future

"Monte Carlo" just means running your plan through many possible futures, each with different market returns, and counting how many work out. The method matters. Some tools replay real historical sequences. Others draw random returns from an assumed average and volatility (how much returns swing from year to year).

Neither method is wrong. They answer slightly different questions, which is partly why FIRECalc's two modes gave that forum user 38% and 55.5% for the same plan. A good tool tells you which method it uses.

2. Whether you can see and change the assumptions

Expected return, volatility and inflation drive the result. Can you see the defaults? Can you change them? One user reported that NewRetirement (now Boldin) locked its default rates on the free tier (early-retirement.org). If you can't see an assumption, you can't judge the answer it produces.

3. What "success rate" actually measures

A success rate is the share of simulated futures in which your money fully lasts. It's pass/fail. As the CFA Institute points out, that means it doesn't show how badly the failing scenarios fall short (CFA Institute, Apr 2023). Running dry at 94 and running dry at 78 count as the same failure.

That's not a reason to ignore success rates. It's a reason to read them as odds, not a grade. It also helps to have a benchmark. Morningstar's 2025 research puts the safe starting withdrawal rate at 3.9%. That's the rate at which money still lasts in 90% of simulated 30-year retirements (Morningstar, The State of Retirement Income 2025, Dec 2025). Morningstar judges it by the share of futures that work, not by an average return.

4. Whether spending can flex

Real retirees often cut back when markets fall. Few tools model that, a point made bluntly on The Peak FP podcast (Retirement Planning Tools Will Ruin Your Retirement). A tool that assumes fixed spending in every future may understate your odds if you're willing to adjust. If you aren't, it's closer to right. Know which assumption your tool is making.

5. How long the plan runs

According to the Social Security Administration, about one in three 65-year-olds may live to at least 90 (SSA, Retirement Information for Medicare Beneficiaries, 2026). A plan that ends at 85 is quietly betting against a third of retirees. Check the default end age. Then check whether you can extend it.

6. How health care is handled

Fidelity estimates that a 65-year-old retiring in 2025 will spend $172,500 on Medicare premiums, deductibles and prescriptions over retirement. That figure doesn't include long-term care (Fidelity Investments, 2025 Retiree Health Care Cost Estimate, Jul 2025). With a cost that size, it matters whether a tool models health care year by year or folds it into one flat spending number.

7. Run-to-run variation

This one surprises people. Rerun a Monte Carlo plan with identical inputs and the answer can move. One forum user reported FIRECalc's Monte Carlo mode returning anywhere from 69% to 100% across repeated runs (early-retirement.org). Again, that's anecdotal. But it's worth knowing how many simulations a tool runs and whether its result stays steady when you click "run" twice.

8. The practical stuff

These still matter. They just come after the questions above:

• Data entry. Boldin links accounts. ProjectionLab is manual entry only. Linking saves time. Manual entry keeps your logins to yourself.
• Tax and Social Security depth. Roth conversions, claiming age, detailed tax projections. These matter if your situation is complex.
• What the free tier leaves out. Some free tiers drop Monte Carlo entirely or won't save plans. Make sure the free version actually answers your question.
• Price, checked on the day. Reported prices conflict, as the table shows.

A 20-minute test for any tool

You don't need to trust any comparison, this one included. Test the tools yourself:

1. Write down one plan. Age, savings, monthly spending, retirement age.
2. Enter it into two or three tools exactly the same way.
3. Rerun each one three times. Note whether the answer moves.
4. Find the assumptions page. Return, inflation, end age, health care. If you can't find it, note that too.
5. Compare the spread. If the tools disagree widely, the gap is in the assumptions. Now you know what to ask about.

Nearly half of workers skip even the first step. EBRI's 2025 Retirement Confidence Survey found only 52% have estimated the monthly income they'll need in retirement (EBRI/Greenwald, Retirement Confidence Survey 2025, Fact Sheet 3). Writing down one plan already puts you ahead.

Where Monte Climb fits

Here's how we handle the features above. You can judge it against the same checklist.

• Three numbers to start. 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.
• A probability, not a promise. The answer is a success rate, not a single projection based on an average return.
• Runs to 95 by default. You can push it further.
• Health care modeled year by year. The engine charges Medicare premiums and income-based surcharges each year instead of using a flat guess.
• Stress-testing. Break your plan on purpose, before life does.
• William, our AI planner. Ask him things like "Am I on track?", "Can I retire at 62?" or what spending is sustainable. Talk to him like you would a friend.
• Privacy. It runs in your browser, and nothing is saved until you say so.
• Cost to try. A 7-day trial for $1.

What we're not: a financial advisor. Monte Clim is planning software, not advice. If you need detailed tax strategy or estate work, a fuller planner or a professional may suit you better.

The bottom line

The best retirement planning software is the one whose answer you understand. Before you look at features, look at the engine, the assumptions, the end age and how health care is handled. Then read the result as odds.

Want to see your own odds? Enter your three numbers and show my answer. Or ask William whether you're on track.

Frequently asked questions

What is the best retirement planning software?

No single tool is best for everyone. Common choices include Boldin, ProjectionLab, MaxiFi, Pralana, the free planners from Empower and Fidelity, and free calculators like FIRECalc. Pick one that shows how it simulates markets, lets you see and change its assumptions, plans to an age like 95, and models health care costs.

Why do retirement calculators give different results for the same plan?

Mostly because they make different assumptions. A 2019 study reported by NAPA found that investment return assumptions caused the biggest differences between calculators. Tools also differ in whether they replay historical returns or generate random ones, and in how long the plan runs.

What does a Monte Carlo success rate mean?

It's the share of simulated futures in which your money lasts for the whole plan. Because it's pass/fail, it doesn't show how far short the failing scenarios fall. Read it as odds, not a guarantee.

Is free retirement planning software good enough?

Sometimes. Check what the free version leaves out. Reviews note that Boldin's free tier lacks Monte Carlo simulation and detailed tax projections, and that ProjectionLab's free tier can't save plans. If the free version answers your question clearly, it may be enough.

How much does retirement planning software cost?

Published reviews disagree. Boldin's paid tier has been reported at $120, $144 and $168 a year. ProjectionLab Premium has been reported at $129 a year. Always check the vendor's own pricing page. Monte Climb offers a 7-day trial for $1.