Portfolio Runway Calculator
Calculate your portfolio runway.Compare five portfolio paths.
See how many years cash, bonds, stocks, gold, or a Bitcoin power-law scenario could fund your inflation-adjusted spending—if you stop working now or later.
Calculate your runwayYour portfolio runway
How long could your portfolio fund your lifestyle?
Portfolio, lifestyle, and when you stop working—then compare your runway across five asset scenarios.
Each forecast grows the selected asset path, then subtracts your spending.
If you retire now, the Bitcoin path keeps funding your lifestyle — portfolio still grows while you spend
Asset runway race
Compare five early-retirement portfolio scenarios
How long $ 1,500,000 lasts while spending $ 150,000/year starting now, with 3% spending inflation — across five asset assumptions.
Bitcoin power-law scenario
Under the power law, Bitcoin is the only path that keeps funding this lifestyle without running dry — cash lasts about 10 yrs.
That optimism comes from the model. Sequence risk, volatility, and a broken curve could still force you to sell. Compare stocks and gold before you treat a 60+ year result as a plan.
Scenarios are educational estimates with smooth returns. Real markets swing; past performance and fitted models are not guarantees.
Portfolio forecast
Bitcoin balance while you spend
Drawdowns start immediately under your spending plan. Watch whether the line goes to zero or keeps climbing.
Takeaway
On the Bitcoin path, my $1.5M portfolio has 60+ years of runway at $150k/yr (Wealthier Today).
Runway, not targets
How long your portfolio could fund your lifestyle.
Dollar spending
No mandatory 4% rule input.
Bitcoin power law
Optimistic hodler scenario built in.
Private by design
Math runs locally in your browser.
Built for portfolios you already have
Classic FIRE asks “when do I hit the number?”
This tool asks the question people with meaningful portfolios actually have: if I live on $X per year, how long does each asset keep me funded — and does waiting a year or two change the answer? Background on the movement: FIRE explained.
Your stack
What you already own. This is your starting point, not a future goal.
Your lifestyle
Annual spending in dollars — rent, food, travel — not a percentage of the portfolio.
When you stop
Retire now, or work 1–2 more years while the stack compounds (and optionally keep investing).
Asset path
What the money sits in. Cash may deplete quickly; equities can last longer; modeled Bitcoin may clear the 60-year horizon.
Why this calculator
Withdrawal rate is an output, not the plan
The 4% rule is a useful historical benchmark — but an awkward primary input when you already know your lifestyle and your stack. We grow each asset path, subtract your spending, adjust for inflation, and show when the balance hits zero (or never does). Same multi-asset twist as our wage inflation calculator.
- Starts from the portfolio you already have — not a savings target you must hit first
- Uses your real annual spending in dollars (no arbitrary % withdrawal goal)
- Compares cash, bonds, stocks, gold, and a Bitcoin power-law scenario side by side
- Answers “can I retire now, in 1 year, or in 2 years?” with runway forecasts
Cash & bonds
Honest baseline: with a high spend rate, the balance drains down on a timeline you can almost predict to the year.
S&P 500
Long-run equity growth can stretch a lifestyle for decades — still sensitive to bad return sequences.
Gold
Hard-money middle ground: better inflation ballast than cash, usually less upside than stocks.
Bitcoin power law
Optimistic time-based curve. Great for “what if the model holds?” scenarios — not a guarantee.
A different planning metric
What is portfolio runway?
Portfolio runway is the number of years an investment portfolio could fund a chosen lifestyle under a stated return, spending, and inflation scenario. It turns a portfolio balance into a duration you can compare across asset assumptions.
Your FIRE number is the destination. Portfolio runway is the distance your current portfolio may carry you. For the target and estimated date, use our traditional FIRE calculator.
Three questions, three useful outputs
Use the metric that matches the decision you are making.
| Metric | Question | Output |
|---|---|---|
| FIRE number | How much do I need? | Target portfolio |
| FIRE date | When might I reach it? | Estimated year and age |
| Portfolio runway | How long could my current portfolio fund my lifestyle? | Years of funded spending |
For Bitcoiners
What the power law is doing here
If most of your net worth is Bitcoin, the useful question is rarely “what % should I withdraw?” It’s “if this asset keeps following its long-term curve, does my lifestyle still work?” We model that curve as the Bitcoin lane.
Learn about Bitcoin- Bitcoin’s long-term price history looks roughly linear on a log-log chart of price vs. days since the genesis block.
- This tool applies that curve as a growth engine while you spend — so you can ask whether a large stack funds life indefinitely under the model.
- A large dollar spend can still equal a double-digit percentage of your portfolio. As long as modeled power-law growth outpaces that spending, the balance can keep rising through the forecast.
- The smooth forecast leaves out volatility, drawdowns, and the chance the curve breaks. Treat 60+ years as a bullish scenario to compare against stocks and gold — not a guarantee.
How to use the results
Optimistic scenarios, grounded decisions
If one scenario lasts the full model horizon while another runs out sooner, that contrast is the point. Make big life changes only after the conservative return paths and higher spend-inflation cases still feel livable.
Planning checklist
- Enter the portfolio and annual spend you actually have — not a 4% textbook target.
- Toggle retire now vs. wait 1–2 years to see how much delay buys you on each path.
- If only Bitcoin clears the 60-year horizon, ask whether you can stomach multi-year drawdowns without selling to cover your lifestyle.
- Stress-test higher spending inflation and a stock-only path before you give up a paycheck.
Levers that change your runway
What actually moves the forecast
Spending level
Lower spending buys more years on every path — often more than tweaking return assumptions.
One more year of work
Delaying retirement lets the stack compound (and optional contributions add fuel).
Asset mix
Cash answers “how long until empty?” Bitcoin answers “what if the model holds?” Both are useful.
Inflation on spend
Rising costs shorten low-return runways fast. Stress-test 0% vs 3–5% inflation.
Portfolio runway FAQ
Common questions
What is portfolio runway?
Portfolio runway is the number of years an investment portfolio could fund a chosen lifestyle under a stated return, spending, and inflation scenario. Your FIRE number is a target balance; portfolio runway is a duration based on the portfolio you already have.
Who is this portfolio runway calculator for?
People who already have a meaningful portfolio and want to test how long it could fund their lifestyle. It is also useful for comparing an optimistic Bitcoin power-law scenario with simplified cash, bond, stock, and gold paths.
What is the difference between a FIRE number and portfolio runway?
A FIRE number estimates how much you need to support retirement at a chosen withdrawal rate. Portfolio runway estimates how many years your actual portfolio could cover inflation-adjusted spending under a selected asset scenario. One is a destination; the other is the distance your current portfolio may carry you.
Why isn’t there a withdrawal-rate input?
Withdrawal rate is treated as an output. Enter the dollars you plan to spend and the calculator shows what percentage of your portfolio that represents when withdrawals start. Use the traditional FIRE calculator if you want to choose a withdrawal rate and calculate a target portfolio.
How does the portfolio runway forecast work?
Each asset path grows month by month under its return assumption. Until your chosen retirement date, optional monthly investments are added. After retirement, annual spending is withdrawn monthly and inflated each year. The result reports when the portfolio reaches zero or whether it lasts the full 60-year horizon.
What is the Bitcoin power law used here?
It is a long-term model popularized by Giovanni Santostasi in which Bitcoin’s modeled fair price scales with days since the genesis block. The calculator uses month-to-month growth from that curve for the Bitcoin scenario. It is optimistic and not a guarantee that the historical pattern will continue.
Why can Bitcoin show 60+ years of runway while cash runs out?
If modeled growth remains above the combined drag from spending and inflation, the balance can keep rising throughout the 60-year horizon. Cash may not outgrow a high spending rate, so principal is consumed. A 60+ result means the portfolio did not deplete within this model’s horizon; it does not mean risk-free or unlimited funding.
Are the stock, bond, cash, and gold returns guaranteed?
No. They are simplified fixed annual assumptions with smooth compounding. Real markets have fees, taxes, crashes, multi-year drawdowns, and sequence-of-returns risk that this deterministic model does not capture.
Does this include taxes, fees, Social Security, pensions, or part-time income?
No. Treat annual spending as the amount your portfolio must supply after reliable outside income, and leave room for taxes and investment fees. The calculator does not model account-specific tax rules, health-care shocks, pensions, Social Security, or variable withdrawals.
Does the calculator store my financial details?
No. Inputs are processed locally in your browser and are not submitted through a form.
Try another retirement date
Flip between retire now, one more year, or five — and see which assets still fund your life.
Keep exploring
Turn your numbers into next steps
Dig into the guides behind the math or run a different calculator to round out your plan.
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