Financial scenario planner
See how it plays out, before you decide.
Buy the house? Retire at 55? Start the business? All of those, together?
ifso plays it out year by year, in plain English, with real tax, mortgage, and market math underneath, so you're never deciding blind.
Free to start · No credit card · No bank linking: you type in numbers, we do the math
The status quo
Your biggest money questions don’t fit in a calculator.
Spreadsheets
You could build it yourself: amortization schedules, tax brackets, inflation adjustments… people do. It takes a weekend, breaks quietly, and never quite answers “so am I okay?”
One-off calculators
A mortgage calculator knows your payment. It doesn’t know your 401(k), your raise next year, or what buying the house does to retiring at 55. Every answer is an island.
Heavyweight planners
Cumbersome, unintuitive, and hard to use. Forty inputs before your first answer, and comparing two choices often means rebuilding the whole plan.
There’s a gap between “vibes and a spreadsheet” and $2,000 for a financial advisor. ifso lives in that gap.
How it works
From “what if” to verdict in three steps.
Tell it about your money
Age, income, accounts, the house, the car loan. Guided setup, plain questions, a few minutes. No bank passwords; ifso never connects to your accounts.
Add a decision to your timeline
Click an age. Buy a home, retire, start a business, add a kid’s expenses. One event, and ifso handles the mortgage amortization, the taxes on the down payment, the ripple effects through every year after.
At age 34...
…and a dozen more: sell the car, open an account, claim Social Security
Read the verdict. Then compare.
Not a chart to interpret, but an answer: “Funds retirement through age 90, spending $93k/yr.” Duplicate the plan, change one thing, and see both futures on the same chart with the difference in dollars.
Free to start · No credit card
See it in motion
Watch a plan come together.
A full walkthrough: build a plan, read the verdict, then duplicate it and compare a second future side by side.
Spin up a fresh plan and name it. Here, it's “Retire at 65.”
The verdict
Most tools draw a line. ifso tells you what it means.
Every plan gets a verdict up top: does the money last, to what age, and what you can actually spend. If a plan falls short, ifso tells you when, “savings run out at 81,” so you know exactly what you’re fixing.
When you compare two plans, it names the winner and why: a plan that stays solvent beats one that dies with a bigger house.
The same header, two different plans. One change can flip it.
Simple surface, deep engine
One click. Everything underneath.
Add “Buy a $450k home at 34” and ifso quietly does what a financial analyst would:
- Amortizes the mortgage month by month: principal, interest, property tax, insurance
- Pulls the down payment from your investments and pays the capital-gains tax on the way out
- Grows the home’s value, tracks your equity, and frees up cash flow when the loan ends
- Models the whole household: two incomes, married filing jointly, per-person 401(k) limits
- Re-runs your entire future (taxes, contributions, retirement) through age 90
You see one event on a timeline. It sees four hundred calculations. That’s the deal.
And not just the house: anything can change at any age, from raises and expenses to Social Security claimed anywhere from 62 to 70. Change one number, and every year after it recalculates: taxes, amortization, growth, withdrawals, the verdict.
Monte Carlo
“Probably fine” is not a plan. Get the odds.
Markets don’t return 7% every year. Run your plan through 1,000 simulated market histories, each drawing randomized year-by-year returns around your own growth assumptions, and get a straight answer: an 87% chance the money lasts. See the range of futures, great decade or terrible decade, not just the average one.
The full engine and one saved plan are free, forever. Pro adds unlimited plans, side-by-side Compare, and Monte Carlo odds for $69/year.
The decision is coming either way.
Make it with the math done.
ifso is what you open at a real fork in the road, not another dashboard to check every week. Bring the question, leave with a number.
Free to start · No credit card · First verdict in minutes