You’ve seen the multiverse in movies. Every choice spawns a new branch of reality. Now apply that to money.
It’s the same method — Monte Carlo simulation — that powers the planning software financial professionals use. Arthea applies it with Canadian tax math estimated in.
The moment you click “Forecast,” Arthea simulates 10,000 versions of your financial life. Each branch plays out with different markets, different inflation, different luck. In some, you compound beautifully and retire early. In some, the market has a brutal decade in your 30s and you spend years catching up. In some, you simply cruise. Arthea models them all, so you can see the range of who you might become — financially — by 30, by 50, by retirement.
The one thing to know about money. Compounding is wild over long horizons. $5,000 invested at 25 isn't $5,000 at 75 — it's more like $100,000 if the market behaves, maybe $40,000 if it doesn't. The earlier you start, the more time the math has to work for you instead of against you.
You get a range, not a single number
Arthea branches your required forecast timeline 10,000 ways. Markets are random — up most years, down some, occasionally a crash. Each branch rolls the dice differently. The result isn't one line. It's a band: the bottom 10% of your futures, the median, the top 10%.
That range is the answer. A single number pretending to be the answer is lying to you.
Your situation is the input
Accounts, savings, planned contributions, future income, what you’ll spend, taxes. That’s the starting point — the rest is simulation.
A caution about average returns
Most software draws its chart from a single “average return,” so the line looks smooth and always rising. Markets don’t behave that way — up 30% one year, down 22% the next. Arthea models the swings to capture sequence risk: a couple of bad years right at retirement hurt far more than the same years two decades earlier.
It blends three economic stories
Instead of betting on one forecast, Arthea weighs three plausible futures — calmer markets, status-quo, persistent inflation — by how cautiously you choose to plan.
The asymmetry. Being wrong on the optimistic side means you work a couple more years. Being wrong on the pessimistic side means you had more than you needed when you die.
Only one of those ruins a life.
The real number, not the pre-tax fantasy
RRSPs, TFSAs, RRIFs at 71, CPP and OAS, the OAS clawback — tax is estimated every year of every simulated branch. Most tools bolt tax on at the end, if at all. Arthea runs it the whole time, so the wealth you see is closer to what you'd actually keep.
Every Canadian province and territory.
| Year | Taxable | Est. tax |
|---|---|---|
| 2044 | $1.41M | $655K |
| 2046 | $1.36M | $632K |
| 2048 | $1.48M | $694K |
| 2050 | $1.16M | $546K |
Nobody can predict tomorrow — let alone the next 60 years. Arthea can’t either. What it can do is show whether the choices you’re making now likely add up to financial freedom, or whether they’re fragile and depend on everything going right.
Good plans hold up across most branches. Fragile plans look great in the average case, then collapse the moment anything goes wrong. Arthea helps you tell the difference — early enough to do something about it.
Arthea is not a replacement for a financial advisor, and not financial advice. It's built to help you explore your financial future, then have sharper conversations with the people qualified to give advice. Every number you see is an estimate from a model, not a recommendation.
Your data is encrypted, in transit and at rest. Sign-in goes through Google, so we never see or store a password. Administrative access to the production environment is limited to operational issues and logged. You can delete your household and all its data at any time.
The forecast doesn’t need to know who you are. Names, dates of birth, your spouse’s and children’s names — none of it drives the math. You’re encouraged to obfuscate:
For dates of birth, only the year matters. Your Google sign-in exists only to keep your account secure — nothing personal feeds the calculations, just the financial numbers you enter. Just remember: garbage in, garbage out.