How Long Will My Money Last in Retirement?
The question every retiree and pre-retiree needs to answer. How long your savings last depends on three variables: how much you have, how much you spend, and what your investments return. Here's the math across every realistic combination.
All growth estimates assume 7% average annual returns — a conservative long-run average for a diversified stock/bond portfolio. Real results will vary.
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Use the FIRE Calculator →Portfolio longevity table
Years until depletion assuming 7% average annual returns and fixed monthly withdrawals. “∞” means the portfolio is expected to grow faster than it's drawn down.
| Portfolio | $2k/mo | $3k/mo | $4k/mo | $5k/mo | $7k/mo | $10k/mo |
|---|---|---|---|---|---|---|
| $500k | ∞ | 51 yr | 19 yr | 13 yr | 8 yr | 5 yr |
| $750k | ∞ | ∞ | ∞ | 30 yr | 14 yr | 8 yr |
| $1M | ∞ | ∞ | ∞ | ∞ | 26 yr | 13 yr |
| $1.5M | ∞ | ∞ | ∞ | ∞ | ∞ | 30 yr |
| $2M | ∞ | ∞ | ∞ | ∞ | ∞ | ∞ |
| $3M | ∞ | ∞ | ∞ | ∞ | ∞ | ∞ |
Withdrawal rate rules of thumb
Expected longevity based on withdrawal rate for a typical balanced portfolio.
| Withdrawal Rate | Expected Longevity | Notes |
|---|---|---|
| 2% | 55+ | Near-perpetual — portfolio likely grows |
| 3% | 40–50+ | Very safe for 40-year retirements |
| 3.5% | 35–45 | Recommended for early retirees (40-45yo) |
| 4% | 30–35 | Classic Trinity Study standard |
| 5% | 20–25 | Elevated risk over long retirements |
| 6%+ | 12–18 | High depletion risk — consider adjusting |
The math behind the table
Portfolio depletion formula
n = −ln(1 − PV × r / PMT) / ln(1 + r)
Where: PV = portfolio, r = monthly rate (7%/12), PMT = monthly withdrawal, n = months
When the portfolio return exceeds the monthly withdrawal, the formula returns a negative value — meaning the portfolio grows indefinitely. This is the math behind “∞” in the table above. For example, $1M at $2,000/month: the portfolio earns ~$5,833/month at 7% returns while only withdrawing $2,000 — it grows by $3,833/month.
Important: this model assumes constant returns. Real markets have volatile years. A bad sequence of returns — especially in years 1–5 of retirement — can significantly reduce actual longevity vs. these projections. Our FIRE Calculator runs Monte Carlo simulation with variable returns to show you a more realistic probability range.
Frequently asked questions
How long will my retirement money last at 4% withdrawal?
At a 4% withdrawal rate with 7% average annual returns, a retirement portfolio is designed to last 30+ years historically. The Trinity Study found that 4% has historically succeeded 95%+ of the time over 30-year periods for a balanced stock/bond portfolio. For early retirees with 40-50 year horizons, 3–3.5% provides more safety.
What is the biggest risk to how long my money lasts?
Sequence of returns risk — the order in which returns occur — is the primary threat. A 30% market decline in your first 3 years of retirement can permanently impair your portfolio even if average returns are positive over 30 years. This is why cash buffers (1–2 years of expenses) and flexible spending strategies matter so much in early retirement.
How do I make my retirement money last longer?
Four proven strategies: (1) Reduce your withdrawal rate — each 0.5% reduction dramatically extends portfolio life. (2) Delay Social Security — waiting from 62 to 70 can increase benefits by 77%, reducing portfolio dependence. (3) Flexible spending — reduce spending by 10–20% in bad market years. (4) Part-time income — even $1,000/month reduces portfolio withdrawals by $360,000 over 30 years at 4%.
Does investment return matter as much as withdrawal rate?
Both matter, but the withdrawal rate is the variable you control most directly. Moving from 5% to 4% withdrawal has a larger impact on longevity than moving from 6% to 7% expected return. Focus on what you can control: spending flexibility, withdrawal rate, and having a plan for bad market years. Return assumptions are outside your control.
Should I include Social Security in my longevity calculation?
Yes — Social Security is one of the most valuable longevity tools available. If you receive $2,000/month from SS starting at 67, you're effectively withdrawing $24,000/year less from your portfolio. On a $1M portfolio, that reduces your effective withdrawal rate from 4% to 1.6% — dramatically extending how long your money lasts.
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Enter your savings, contributions, expenses, and Social Security. Our Monte Carlo simulation shows your exact probability of never running out of money.
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