Retirement Drawdown Planner
Most retirement calculators stop at 'how much do I need.' This one starts where they stop: given your portfolio, annual spending, and expected returns, see year-by-year whether your money lasts — and what happens if returns disappoint.
Your retirement
Big expenses (new roof, college) or income (home sale, pension start) landing in a specific year. Applied to every strategy.
Small changes, big difference
Each lever re-runs your constant dollar strategy with one change.
All three strategies, your numbers
Same portfolio, same market assumption — only the withdrawal rule changes.
| Strategy | Years funded | Worst-year spending | Ending balance |
|---|---|---|---|
| Constant dollarselected | 30 / 30 | $40,000 | $1,811,362 |
| % of portfolio | 30 / 30 | $42,400 | $1,687,769 |
| Guardrails | 30 / 30 | $40,000 | $1,811,362 |
“Worst-year spending” is the smallest annual withdrawal in nominal dollars — flexible strategies trade a lower floor for a portfolio that never runs dry.
Portfolio balance, year by year
Stress test
Drag expected return down to 3–4% and watch what happens — most plans that look safe at 6–7% break under sustained weak returns. Try raising inflation too: inflation is the quiet killer because your withdrawals keep growing while the portfolio doesn't. Then flip the strategy to guardrails and see how a flexible spending rule rescues a fragile plan.
Honest caveat: this is a fixed-return model, not a Monte Carlo simulation. Real markets vary year to year, and bad returns early in retirement hurt far more than the same average spread evenly (sequence-of-returns risk). Treat a plan that only barely survives here as fragile.
How the math works
Each simulated year, the portfolio grows by the expected return, then that year's withdrawal is taken out. The withdrawal starts at your annual spending and compounds with inflation every year, so purchasing power stays constant. If the balance hits zero, the plan is marked depleted in that year and the simulation stops.
This is a deterministic model: one fixed return, every year, no volatility. It answers "does the math work if returns cooperate?" — it does not model the far more dangerous case of a market crash in your first five retired years. A plan that survives here with room to spare is robust; a plan that barely survives is not.
Taxes, fees, Social Security, and required minimum distributions are not modeled — all of them move the real answer. Think of this as the feasibility check before the detailed planning, not the plan itself.
Common questions
What is the 4% rule, and does it still hold?+
The 4% rule (Bengen, 1994) found that withdrawing 4% of the portfolio in year one, then adjusting for inflation, survived every 30-year US retirement historically. It's a rule of thumb, not a guarantee — today's bond yields and valuations differ from history, and it says nothing about 40-year horizons or leaving a legacy.
Why does inflation matter so much in the model?+
Because your spending compounds while your portfolio may not. At 3% inflation, a $40,000 lifestyle costs $97,000 in 30 years. If returns merely match inflation, you're withdrawing a growing slice of a stagnant pie — which is exactly how portfolios die quietly.
What is sequence-of-returns risk?+
Two retirees can earn the same average return and get opposite outcomes if one's bad years come first. Withdrawing during a crash locks in losses on shares sold low — the portfolio can't recover even when markets rebound. This calculator's smooth fixed return understates this risk; a Monte Carlo simulation with randomized yearly returns captures it.
Should I adjust spending when markets fall?+
Dynamic strategies (spend less after down years, more after good ones) dramatically improve survival odds versus rigid inflation-adjusted withdrawals. Research on guardrails-style rules shows small spending flexibility buys a lot of safety — worth modeling if your spending has discretionary room.