Retirement · Planning
A retirement Monte Carlo that runs on your own machine.
A Monte Carlo simulation runs your retirement plan many times over against different market luck — good years, bad years, and the order they arrive in — so you see a range of outcomes instead of one optimistic straight line. GlidePath runs 1,000 simulated lifetimes of your plan, and it does it locally: your balances and assumptions never leave the computer, and there’s no account to create.
Most retirement Monte Carlo tools live in a web calculator — one that wants your data, or a subscription.
The good simulators are usually a website you feed your balances into, or a planning suite you rent by the month. Either way your numbers go to someone else’s server.
GlidePath is the other shape: the simulation runs inside a desktop-license app you can keep using, on your own computer. The same engine that draws your glide path runs the Monte Carlo — same inputs, same assumptions — so the range you see is built from the plan you already have, not a stripped-down web form. Your balances never leave the machine.
What it does — and how to read it.
1,000 runs, a fresh draw each year
Each simulated lifetime samples a market return for every year from a normal distribution around the return and volatility you set — with a separate return and volatility for your working years and your retirement years, since most people de-risk as they retire. It reports the share of runs where the money lasts the whole plan, so a single market path can’t flatter the answer.
Sequence-of-returns risk, in today’s dollars
Because each year is drawn on its own, the order of good and bad years matters — a crash early in retirement hurts more than the same crash later, and the simulation shows it. Every balance is inflation-adjusted to today’s dollars, and you see the 10th, 50th, and 90th percentile outcome for each year: a rough-but-honest bad, middle, and good case.
Built on your real plan
It works in Social Security (with claim ages, spousal and survivor benefits), a pension, workplace equity vesting while you’re still working, your contributions, and how a household’s spending shifts when one spouse outlives the other. It runs from a fixed seed, so when you change an assumption the number moves for a real reason — not because the dice landed differently.
What it doesn’t pretend to do.
A Monte Carlo is a way to see a range, not a forecast. GlidePath is honest about the edges of the model rather than dressing the output up as certainty.
It samples returns from a normal distribution around your assumptions — it is not a historical-sequence (bootstrap) engine, so it won’t replay a specific past crash or a fat-tailed extreme, and the answer is only as good as the return, volatility, and spending you give it. It assumes steady inflation-adjusted spending rather than dynamic “spend less in a down year” guardrails, and tax-timing strategy — Roth conversions, the Tax Valley — lives in its own view rather than being re-derived inside every simulated year. The percentages are a planning aid, not a promise: it calculates and shows the ranges, and your CPA or a fiduciary advisor confirms the plan for your situation.
Run the numbers without handing them over.
$129 desktop license for Personal — retirement planning and the Monte Carlo are in the core tier. Your plan stays in a plain file on your own computer.
GlidePath runs the simulation and shows the ranges — it isn’t financial advice. A Monte Carlo result depends on the assumptions you enter and can’t predict actual markets; for your specific plan, confirm with a qualified professional.
Retirement Monte Carlo, answered
Can I run a retirement Monte Carlo simulation without connecting my bank?
Yes. GlidePath runs the simulation entirely on your own computer — you enter your plan (balances, return and volatility assumptions, spending, and Social Security and pension timing) and it runs locally. There is no account and nothing is uploaded.
How many scenarios does it run, and what does it show?
It runs 1,000 simulated lifetimes, sampling each year's market return from the return and volatility you set. It reports the share of runs where your money lasts the whole plan, plus the 10th, 50th, and 90th percentile balances for each year in today's dollars.
Does it model sequence-of-returns risk?
Yes. Each year draws its own return, so the order of good and bad years matters — a downturn early in retirement hurts more than the same one later — and the simulation reflects that. It is a parametric model, not a historical replay, and it is not financial advice.