4-Bucket Retirement Calculator Buckets: 3 / 7 / 5 / remainder Refill only when R4 ≥ threshold Monte Carlo (10,000 runs)

This calculator is a 4-bucket retirement simulator that models spending over time while segmenting your portfolio into three “runway” buckets (3 / 7 / 5 years of withdrawals) plus a long-term growth bucket (the remainder). Each year it applies an inflation-adjusted withdrawal (net of Social Security), then applies bucket-specific returns that are driven by a correlated market shock plus bucket-level volatility limits (floors/caps) so safer buckets don’t swing like equities. A refill rule controls when money is redistributed back into Buckets 1–3: only when Bucket 4’s annual return meets or exceeds a user-defined threshold; otherwise, buckets “freeze” and no transfers occur. The “Run Monte Carlo” button repeats the simulation thousands of times using the same assumptions to produce a distribution of possible ending balances, along with survival and “beat starting balance (inflation-adjusted)” rates. It’s used to stress-test how resilient your bucket strategy is to bad sequences of returns and inflation, and to compare policy choices like refill thresholds, spending levels, and allocation risk.

Starting

Spending

If R4 ≥ threshold ⇒ REFILL. Otherwise ⇒ FREEZE. This simulates real conditions where we don't touch bucket 4 to refill the other three buckets when markets are down, which is the strength of the four-bucket system.

Base Returns (Nominal %)

Bucket 1: Duration: 3 years. Years of Retirement: 1-3. Asset Examples: 100% Cash/Money Market/Ultra-Short Bonds.
Bucket 2: Duration: 7 years. Years of Retirement: 4-10. Asset Examples: 25% Stocks/75% Fixed Income (Corporate/TIPS)
Bucket 3: Duration: 5 years. Years of Retirement: 11-15. Asset examples: 60% Stocks/40% Bonds (the classic balanced fund).
Bucket 4: Duration: Remainder. Years of Retirement: 16+. Asset examples: 90%-100% Growth Equities (Nasdaq/S&P500).

Social Security (Today’s $)

Integrate Social Security payments to reduce your withdrawal amounts. Calculate your estimated annual Social Security benefit at ssa.gov/myaccount

Correlated Market Shocks

Neutral: market shocks are symmetric around zero (up and down are equally likely).
Slightly pessimistic: small bias toward negative years. Positive spikes are a bit less frequent; drawdowns are a bit more common.
Pessimistic: stronger negative skew. Big up years are rarer; negative years occur more often and tend to be deeper.
Implementation detail: the simulator draws a “market shock” each year and applies a mild (slight) or stronger (pessimistic) downward skew to that shock before it is correlated into each bucket.
Each year we draw one market shock M. Each bucket gets a correlated shock + a bucket-specific shock, then is clamped by its floor/cap.

Bucket Shock Scope + Floors/Caps (Nominal %)

Floor/cap prevents unrealistic safe-asset behavior; all are editable.

Inflation (Stochastic)

Each year’s inflation is clamp(base + shock, low, high). If you enter them reversed, the calculator auto-fixes.