These calculators are simple educational tools. They take the numbers you enter, apply a published formula, and return a result. Your data is not transmitted, stored, or shared.
I am not a financial advisor. I am a software engineer and the author of Debugging Your Personal Finance. I am not registered with the Ontario Securities Commission (OSC), the Canadian Investment Regulatory Organization (CIRO), the Financial Services Regulatory Authority of Ontario (FSRA), or any equivalent body in any jurisdiction. Nothing on this page is personalized financial, investment, tax, legal, retirement, insurance, or accounting advice, or a recommendation of any specific product, account, broker, fund, ticker, or strategy.
The calculators make simplifying assumptions (constant returns, constant expenses, no taxes, no fees, no behavioural variance, no sequence-of-returns risk). Real markets and real lives do not behave this way. Past performance and historical studies are not guarantees of future results. Outputs are estimates and illustrations, not forecasts.
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"How much do I need invested before work becomes optional?"
If you spend $60,000 a year, you need $1.5 million: $60,000 × 25 = $1,500,000. The magic integer 25 is the inverse of the 4% safe withdrawal rate (SWR).
— Debugging Your Personal Finance, Chapter 4
Based on the 4% safe-withdrawal heuristic (Bengen 1994; Trinity Study 1998). Rule of thumb, not a guarantee.
From Chapter 4 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"If I save X% of my take-home pay, when do I reach FI?"
Saving 10% of your income means working 42 years, but raising the savings rate to 50% cuts that to 15 years, so you have effectively bought back 27 years of your life.
— Debugging Your Personal Finance, Chapter 13
Assumes constant real return and constant savings rate. Result is independent of your absolute income — the same answer for $50k earners and $500k earners.
From Chapters 3 and 13 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"How much future wealth do I burn for every year I delay starting?"
Time (t) is an exponent, and the cost of waiting is exponential.
— Debugging Your Personal Finance, Chapter 7
If you start today: —
If you delay: —
Cost of waiting: —
Compares two deterministic compound paths. Real returns vary year-to-year; volatility is not modeled.
From Chapters 7 and 15 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"Can a late start out-save an early one?"
The early saver's initial effort compounded to approximately $1,050,000. The late saver contributed three times as much cash but still trails by more than $100,000 — fighting against the exponential math of those first ten lost years.
— Debugging Your Personal Finance, Chapter 7
Early saver at retirement (principal: —): —
Late saver at retirement (principal: —): —
—
Illustrative comparison at constant real return. Actual outcomes depend on market sequence.
From Chapter 7 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"What do I actually earn per hour, after tax, commute, and job-related costs?"
Consider someone earning $100,000 a year. Dividing that salary by a standard 2,000-hour work year suggests $50 an hour. But once we add the hidden costs and shadow hours, the real rate comes out to $25.22 an hour.
— Debugging Your Personal Finance, Chapter 12
Net income: — · Total hours: —
Your real hourly wage: —
A conceptual reframing of your wage net of work-related time and costs. The categories you include or exclude are subjective — treat the output as a thinking tool, not a payroll figure.
From Chapter 12 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"What does this purchase actually cost my future self?"
The car does not cost $59,000. It costs you nearly half a million dollars in your future net worth.
— Debugging Your Personal Finance, Chapter 12
True future cost: —
That's — of your life energy.
Compounds the price at a constant real return. Does not model depreciation, replacement cost, or use value of the item.
From Chapter 12 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"If I stopped working today, how many days until my liquid money runs out?"
Against a liquid net worth of $145,000 and a daily burn rate of about $320, that mathematically works out to 453 days of absolute freedom before system shutdown.
— Debugging Your Personal Finance, Chapter 10
Days of Freedom: —
Equivalent to —
Daily expenses: —
Measures how many days your liquid portfolio could cover your current expenses. Does not account for taxes, inflation drift, healthcare costs, or longevity risk.
From Chapters 5 and 10 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"What is my net worth if I stop lying to myself about my house and my car?"
Standard balance sheets hide liquidity risk. You might have a net worth of $1M, but if $900k is in your house, you have zero liquidity. Freedom Net Worth is simply Q1 − Q3.
— Debugging Your Personal Finance, Chapter 5
Standard net worth: —
Liquidation net worth (8% home haircut per Ch. 10): —
Freedom Net Worth (Q1 − Q3): —
Liquidation haircut on real estate is illustrative; actual transaction costs vary. This calculator does not advise on which quadrant your future contributions should flow into.
From Chapters 5 and 10 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"Given my age and income, am I an over- or under-accumulator of wealth?"
If income is a vanity metric, what is the value metric? Stanley & Danko gave us a simple formula: Expected Net Worth = (Age × Income) / 10.
— Debugging Your Personal Finance, Chapter 3
Expected net worth: —
Your ratio: —
Classification: —
From Stanley & Danko's The Millionaire Next Door. PAW = Prodigious Accumulator (ratio ≥ 2.0). UAW = Under Accumulator (ratio < 0.5). The formula is a heuristic, not a financial plan.
From Chapter 3 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"How long does it take my money to double — and how many doubles do I have left?"
Divide 72 by your annual rate of return and you get the approximate number of years it takes for your money to double.
— Debugging Your Personal Finance, Chapter 7
Time to double: —
Doubles remaining: —
$1 today becomes: — at retirement (exact compounding)
The Rule of 72 is an approximation derived from the natural log of 2 (≈ 0.693). The "exact" multiplier above uses $(1+r)^t$ for the actual answer.
From Chapter 7 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"How much money and time do I waste paying only the minimum?"
Consumption debt is the radioactive material of personal finance — debt taken on to buy things that lose value immediately, generate zero income, and have no resale value.
— Debugging Your Personal Finance, Chapter 6
Minimum payment: —, total interest —
Aggressive payment: —, total interest —
Money saved by paying aggressively: —
"Minimum payment" here means interest plus the percent-of-principal you set. Real credit cards may use different rules (e.g., a fixed $25 floor). With 1% of principal on a 22% APR card, the balance never effectively pays off — the calculator shows ≥600 months ("decades+") to drive that point home.
From Chapter 6 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"What does my next car decision really cost over 30 years?"
You cannot quit a toxic job if you have a $1,000 monthly car payment.
— Debugging Your Personal Finance, Chapter 6
Loan monthly payment on the expensive car: —
Difference between Strategist and Debtor at the horizon: —
Numbers shown are terminal wealth at the horizon from investing the cash flows each strategy frees up, modeling a single purchase held for the full horizon. The book's own 30-year worked example instead has each buyer replace their car every decade (three purchase cycles), so plugging in the book's exact prices here will not reproduce its cited totals — use this calculator to test your own one-time decision, not to re-derive the book's figures. Lower numbers in the Debtor / Saver columns = more opportunity cost. The Strategist invests the upfront price delta plus the loan-payment-equivalent stream.
From Chapter 6 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"Should I throw extra cash at my mortgage or invest it?"
Paying off a 6% debt is a guaranteed, tax-free 6% return. If your mortgage rate is above 6%, paying it down is therefore the superior choice.
— Debugging Your Personal Finance, Chapter 6
Mortgage payoff in — if you add the extra.
—
Both paths compared at the end of the original mortgage term. The invest path subtracts capital gains tax on gains; the payoff path invests $standard+$extra after the mortgage is gone. Real-life: factor in your liquidity preference, your tax-deferred account room, and your behavioural ability to actually invest the surplus.
From Chapter 6 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"I just got a raise. If I let lifestyle absorb part of it, am I closer to FI — or further?"
Each new dollar of lifestyle is not a one-time expense; it permanently raises the nest egg you need by $25.
— Debugging Your Personal Finance, Chapter 13
| Before raise | After raise | |
|---|---|---|
| Expenses | — | — |
| Savings rate | — | — |
| Freedom number (25× expenses) | — | — |
| Years to FI | — | — |
—
Each $1 of recurring expenses you keep adds $25 to the size of the portfolio you need. Even a "modest" 50% lifestyle absorption can flatten the gains from a raise if expenses creep faster than savings.
From Chapter 13 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"How big should my cash buffer be so I don't sell stocks at the bottom of a crash?"
By avoiding forced equity sales during the downturn, the cash buffer holder never had to lock in losses at the worst possible prices.
— Debugging Your Personal Finance, Chapter 8
Target cash buffer: —
—
A standard rule from Ch. 8: 2–3 years of expenses in cash equivalents (money market, short-term Treasuries, CDs) means you never have to sell equities during the first years of a downturn. Adjust to your own risk tolerance.
From Chapter 8 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"When does my portfolio start out-earning me?"
The journey from $0 to $100,000 takes roughly 7.84 years, but the subsequent interval from $100,000 to $200,000 takes only 5.1 years. Once you cross the elbow, the physics of compounding finally changes in your favor.
— Debugging Your Personal Finance, Chapter 15
| Milestone | Years to reach |
|---|---|
| $100k | — |
| $200k | — |
| $300k | — |
| $500k | — |
| $1M | — |
The Flywheel year (when one year of market returns exceeds one year of your contributions): —
Charlie Munger's observation: "The first $100,000 is a bitch, but you gotta do it." After roughly that point compounding outpaces contributions and the math accelerates. Set your inputs to your real numbers to see where that inflection point lands for you.
From Chapter 15 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.
"If I had to invest the same amount I'm about to spend, would I still buy?"
If you want a $400 gadget, you should treat it as if it costs $800, with $400 going to the merchant and another $400 invested for your future self.
— Debugging Your Personal Finance, Chapter 13
True cost (purchase + matched investment): —
What the matched $X grows to in the horizon: —
—
Nick Maggiulli's rule (via Ch. 13): if you want a $X non-essential item, force yourself to invest $X in income-producing assets at the same time. The "true cost" doubles, and if the math still makes sense, the purchase is genuinely worth it.
From Chapter 13 of Debugging Your Personal Finance. Simple calculator · Inputs stay in your browser · Not financial advice.