The short answer
At roughly $65,000 a coin, funding $60,000 a year for a thirty-year retirement from a Bitcoin-only portfolio takes about 23.6 BTC. For $100,000 a year, about 39.4 coins.
That figure comes from a Monte Carlo simulation of 3,000 paths, assuming Bitcoin compounds at 15% a year with 42.5% annualised volatility, withdrawals rise with inflation, and you want a 90% chance of not running out over thirty years. On those assumptions the sustainable withdrawal rate is 3.9%, so the portfolio needs to be $1.54m, which is 23.6 coins.
You should treat that number with considerable suspicion, and the rest of this article explains why. Not because the arithmetic is wrong, but because almost all of it is carried by one input that nobody — including us — can actually know.
Where the usual answer comes from
The standard calculation is: take your desired income, divide by 4%, divide by the Bitcoin price. That gives you this.
| Annual income | Portfolio needed | Bitcoin needed |
|---|---|---|
| $40,000 | $1.00m | 15.4 BTC |
| $60,000 | $1.50m | 23.1 BTC |
| $80,000 | $2.00m | 30.7 BTC |
| $100,000 | $2.50m | 38.4 BTC |
The 4% rule applied naively, at a Bitcoin price of $65,073 (27 July 2026). No model, no volatility, no sequence risk.
It is a clean set of numbers and it is how most articles on this question end. The problem is that the 4% rule was not derived from Bitcoin. It came from the historical record of US stocks and bonds, where the worst sustained drawdowns were roughly 50% and recovery took years rather than a decade. Bitcoin has fallen more than 70% on four separate occasions.
Applying a rule calibrated on one asset’s behaviour to an asset that behaves nothing like it is the single most common error in this entire subject.
What a proper simulation says instead
We ran the same question through the engine that powers our Bitcoin retirement calculator: 3,000 simulated paths, lognormal returns with Bitcoin’s positive skew and fat tails, inflation-linked withdrawals, annual rebalancing, and a 90% survival requirement over thirty years.
| Portfolio | Safe withdrawal rate | Needed for $60k/yr | Bitcoin held |
|---|---|---|---|
| 100% Bitcoin | 3.90% | $1.54m | 23.6 BTC |
| 50% Bitcoin / 50% 60-40 | 4.70% | $1.28m | 9.8 BTC |
| 25% Bitcoin / 75% 60-40 | 4.70% | $1.28m | 4.9 BTC |
| 10% Bitcoin / 90% 60-40 | 4.30% | $1.40m | 2.1 BTC |
| No Bitcoin (60/40) | 3.80% | $1.58m | — |
30-year horizon, 90% survival, 3,000 paths, CPI-linked withdrawals, annual rebalancing, no fees. Bitcoin assumed to return 15% a year with 42.5% volatility.
Look at the first and last rows. A portfolio holding nothing but Bitcoin supported a 3.90% withdrawal rate. A conventional 60/40 supported 3.80%. Those are close to identical — and yet the Bitcoin portfolio was handed an expected return more than twice as high.
This is not an argument against holding Bitcoin. The middle rows of the table make that plain: a portfolio 25% or 50% in Bitcoin sustained a materially higher withdrawal rate than either extreme, and needed the smallest pot of the five. The argument is against holding only Bitcoin while drawing an income from it.
The part that should actually change your mind
Everything above rests on Bitcoin returning 15% a year for thirty years. That is our own published estimate, deliberately set at the conservative end of the institutional range, and it is documented on our methodology page. It is not a fact. It is a guess made carefully.
So the useful exercise is not to compute one number. It is to ask how much the answer moves when that guess is wrong. Here is the same Bitcoin-only portfolio, funding the same $60,000 a year, with only the return assumption changed.
| Assumed Bitcoin return | Safe withdrawal rate | Portfolio needed | Bitcoin needed |
|---|---|---|---|
| 20% a year | 6.30% | $0.95m | 14.6 BTC |
| 15% a year (our estimate) | 3.90% | $1.54m | 23.6 BTC |
| 10% a year | 2.00% | $3.00m | 46.1 BTC |
| 5% a year | — | — | no rate survived |
| 0% a year | — | — | no rate survived |
100% Bitcoin portfolio, $60,000 a year, 30 years, 90% survival. At 5% and 0%, no withdrawal rate we tested — down to 1% a year — survived 30 years in 90% of paths, because 42.5% volatility depletes a portfolio faster than a low return can replenish it.
The requirement swings from under 15 coins to over 46, and then to unachievable at any withdrawal rate we tested. That is the entire span of plausible opinion about Bitcoin’s next thirty years, and it produces answers that have nothing in common with one another.
Anyone who tells you a confident coin count is not telling you about Bitcoin. They are telling you their return assumption, with the assumption hidden.
The finding that actually helps
Run the identical sensitivity test on a portfolio holding 10% Bitcoin alongside a conventional 60/40 core, and something quite different happens.
| Assumed Bitcoin return | Safe withdrawal rate | Portfolio needed | Bitcoin held |
|---|---|---|---|
| 20% a year | 4.50% | $1.33m | 2.0 BTC |
| 15% a year | 4.30% | $1.40m | 2.1 BTC |
| 10% a year | 4.00% | $1.50m | 2.3 BTC |
| 5% a year | 3.80% | $1.58m | 2.4 BTC |
| 0% a year | 3.60% | $1.67m | 2.6 BTC |
10% Bitcoin, 90% in a 60/40 core. Same $60,000 income, 30 years, 90% survival.
Across the full range — from Bitcoin returning nothing at all for three decades to returning 20% a year — the plan needs between 2.6 and 2.0 coins. The whole span of disagreement moves the answer by about half a coin.
Note too that the 10% portfolio beat the no-Bitcoin 60/40 in every scenario — even the one where Bitcoin returns 0% for thirty years, where it still managed 3.60% against 3.80%… which is to say it cost almost nothing to have been completely wrong. That asymmetry is the case for a modest allocation, and it is a much stronger case than the one usually made for it.
What this means in practice
If you are accumulating, the coin count that matters is not a retirement target but a share of your total portfolio. Two to three Bitcoin inside a balanced pot does more reliable work than twenty-four inside a concentrated one, because the first plan survives you being wrong and the second does not.
If you are close to retiring with a Bitcoin-heavy portfolio, the risk is not that Bitcoin falls. It is that Bitcoin falls in your first few years of withdrawals, when selling into weakness does permanent damage. That is the specific hazard, and the fix for it is either a larger buffer of stable assets or a lower initial withdrawal rate — not a stronger conviction.
And if you take one thing from this: when you next see a number for how much Bitcoin you need to retire, ask what return it assumes. If the answer isn’t stated, the number is not analysis.
Methodology
Simulations run with the same engine behind our public tools: 3,000 Monte Carlo paths per portfolio, lognormal returns with Cornish-Fisher adjustment for skewness and excess kurtosis, withdrawals escalated with CPI, annual rebalancing, no management fee, and a 30-year horizon. The safe withdrawal rate is the highest rate, tested in 0.1% steps from 1% to 8%, that left the portfolio solvent in at least 90% of paths. Bitcoin price of $65,073 as at 27 July 2026. Bitcoin’s baseline assumptions — 15% geometric return, 42.5% volatility, skewness 0.80, excess kurtosis 2.00 — are Portfolio Lab estimates set at the conservative end of the published institutional range; all other assets use J.P. Morgan’s 2026 Long-Term Capital Market Assumptions. Full detail on the methodology page. Nothing here is personal financial advice, and a simulation is a description of a model, not a forecast of your life.