Retirement Withdrawal Calculator
Calculate the monthly withdrawal amount a retirement portfolio can sustain at a chosen annual withdrawal rate (e.g., the classic 4% rule). Use it to size your nest egg target or stress-test your spending plan against alternative withdrawal rates.
Last updated: May 2026
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About this calculator
The calculator returns the simple monthly withdrawal implied by an annual withdrawal rate against a portfolio balance: Monthly Withdrawal = (Portfolio Value × Withdrawal Rate / 100) / 12. Variables: Portfolio Value is the total invested balance at retirement (across 401k, IRA, taxable brokerage); Withdrawal Rate is the percentage of the initial balance withdrawn in year one (the classic 'safe withdrawal rate' from Bengen's 1994 study is 4%); other fields (annual return, inflation rate, retirement length) provide context but do not affect this simple monthly figure. The formula is intentionally simple — it does NOT model: (1) the inflation adjustment that the original 4% rule includes (it raises withdrawal in dollar terms each year to keep purchasing power constant), (2) market volatility and sequence-of-returns risk, (3) the Trinity Study's historical-backtest validation showing 4% survives 30 years with 95% probability under a 50/50 to 75/25 stock/bond mix, (4) RMDs from traditional retirement accounts starting at age 73 (or 75 for those born after 1959), or (5) tax differences between accounts. Edge cases: very high withdrawal rates (>5–6%) historically have meaningful failure risk over 30+ year retirements; very low rates (<3%) almost certainly leave a large estate. Use this calculator to size the monthly income, then validate with Monte Carlo simulation or the original Trinity Study before relying on it.
How to use
Example 1 — Classic 4% rule. Portfolio $1,000,000, withdrawal rate 4%. Step 1: annual withdrawal = 1,000,000 × 0.04 = $40,000. Step 2: monthly = 40,000 / 12 ≈ $3,333. Verify ✓. The Trinity Study and Bengen original found a 4% withdrawal of the initial balance, adjusted upward for inflation each year, survived 30-year retirements with >95% probability across all rolling US historical periods since 1926. The often-quoted "$1M nest egg = $40k/yr" comes from exactly this math. Example 2 — Conservative 3.5% rate, larger portfolio. Portfolio $1,800,000, withdrawal rate 3.5%. Step 1: annual = 1,800,000 × 0.035 = $63,000. Step 2: monthly = 63,000 / 12 = $5,250. Verify ✓. A 3.5% rate is more defensible for longer retirements (35–45 years for FIRE retirees in their 40s) or for periods of expected lower future returns (low starting yields + high valuations). Going to 3% on the same portfolio drops monthly income to $4,500 but extends the failure-proof horizon to essentially perpetual.
Frequently asked questions
What is the 4% rule and is it still valid in 2025–26?
The 4% rule comes from William Bengen's 1994 study and the follow-up Trinity Study (Cooley, Hubbard, Walz 1998), which backtested rolling 30-year retirement periods against US historical returns since 1926. They found that withdrawing 4% of the initial portfolio in year one, then adjusting that dollar amount upward for inflation each subsequent year, survived 30-year retirements with about 95% probability across all rolling periods — including the worst (those retiring in 1966 just before the inflationary 1970s). The rule assumes a 50–75% stock allocation; lower equity allocations failed more often. Validity in 2025–26 is contested: critics note that starting valuations (CAPE around 30) and bond yields (10-yr at 4–5%) suggest forward returns may be lower than the historical baseline, supporting a more conservative 3–3.5% rate. Defenders point out that the worst historical 30-year periods already included terrible returns, so 4% has survived worse than today's outlook. The honest answer: 4% is still a useful baseline, but pair it with flexibility — willingness to cut spending in down markets — rather than treating it as guaranteed safe.
How does sequence-of-returns risk affect withdrawal planning?
Sequence-of-returns risk is the danger that bad returns early in retirement permanently damage a portfolio because you are forced to sell at low prices to fund withdrawals. Two retirees with identical average annual returns over 30 years can end up with very different outcomes if one experiences a 30% drop in years 1–3 versus years 28–30. The bad-sequence retiree depletes the portfolio much faster because withdrawals during the downturn lock in losses and leave less capital to recover. This is why the 4% rule includes a margin of safety; it survived the worst sequences in US history. Practical mitigations: hold 2–3 years of expenses in cash and short-term bonds at retirement start (so you can avoid selling stocks during the first downturn), reduce withdrawal in down years (variable spending rules like Guyton-Klinger), or delay retirement by 1–2 years if you retire into a market peak. The classic study showing this is Wade Pfau's sequence-of-returns research, widely cited in retirement planning.
What are the most common mistakes in retirement-withdrawal planning?
The biggest mistake is using nominal portfolio value without accounting for inflation — a "safe" $40k/year in 2025 is only $30k of purchasing power in 2035 if inflation runs 3%. Always adjust for inflation explicitly or use real (inflation-adjusted) returns in your model. The second is ignoring taxes — 401k and traditional IRA withdrawals are fully taxable at ordinary rates, so a $40k gross withdrawal might net only $30–34k after federal + state tax. Roth withdrawals are tax-free but you have to plan the Roth balance in advance. The third is treating Social Security as an afterthought; it provides 25–40% of retirement income for the median household, and the claim age decision (62 vs 67 vs 70) can change lifetime benefits by 75%+. The fourth is using a static withdrawal rate when the portfolio is performing poorly; flexible withdrawal rules (cut 10% in years after a 20%+ market drop) dramatically extend portfolio life. The fifth is forgetting that healthcare costs typically grow 5–7% per year — much faster than general inflation — and dominate late-life budgets.
When should I NOT use a simple withdrawal-rate calculation?
Skip simple rate-based calculations if you have a large pension or substantial Social Security that covers most of your essential expenses — at that point the portfolio is for discretionary spending and emergencies, and withdrawal rate becomes much less binding. Avoid it for very long retirements (40+ years, common for early retirees in the FIRE community); 4% has only been validated for 30 years, and longer horizons need lower rates (3–3.5%) or sophisticated variable-spending rules. Do not use it if you have lumpy expenses (a planned house purchase, a child's college tuition, expected inheritance to pass on); a model that assumes steady spending misses the cash-flow reality. Skip it during the accumulation phase to estimate "how much do I need" — use a future-value-of-annuity calculator or Monte Carlo simulator instead to find the target nest egg, not the withdrawal it can sustain. And do not use it as the sole basis for retirement planning; pair with detailed Social Security claiming analysis, tax planning, and a Monte Carlo simulation (Vanguard, Fidelity, and Personal Capital all provide free versions).
How does the withdrawal calculation change between traditional, Roth, and taxable accounts?
Traditional 401k and IRA withdrawals are taxed at ordinary income rates, so $40k withdrawn might net $30–34k after federal and state tax (assuming 15–25% effective rate). Roth withdrawals after age 59.5 are completely tax-free, so the same $40k from a Roth is $40k spendable. Taxable brokerage withdrawals are taxed only on the gain portion at long-term capital-gains rates (0%, 15%, or 20% federal depending on income), making them tax-efficient. Smart retirees draw from multiple accounts in a planned sequence to manage their marginal tax bracket year by year — often starting with taxable (and harvesting losses), then traditional accounts (filling up lower brackets), and saving Roth for late life or estate planning. Required Minimum Distributions (RMDs) from traditional accounts start at age 73 (or 75 for those born after 1959) and force taxable withdrawal whether you need the cash or not, often pushing retirees into higher brackets. Sophisticated planning includes Roth conversions in low-income years (early retirement before Social Security and RMDs kick in) to reduce future RMD burden.