Retirement simulator

Monte Carlo your retirement plan

Enter your invested balance, retirement age, savings, retirement spending targets and return assumptions. This page estimates your retirement balance, then tests whether that balance can support your spending over time.

Starting point

Set the starting point and how retirement timing should be judged.

Current retirement assets

List the accounts and cash buckets that make up your starting balance. The simulator adds them into invested net worth.

AmountAsset typeAction
Total retirement assets
$0
Bridge-accessible unrestricted assets
$0
Pre-tax retirement assets
$0
Roth assets
$0
Cash
$0
HSA
$0
Unclassified or excluded
$0
Asset bucket reconciliation difference
$0

Bridge Accessible is a cross-category subtotal of unrestricted assets. HSA funds are tracked separately because they are not unrestricted bridge cash.

Saving while working

Enter how much new money is still being added before retirement starts. Budget 401(k) withholding can seed this field until you override it.

Spending targets

Set the three retirement spending targets the simulator can use over time. Extra is calculated when the flexible policy supports more than Life I Want.

Advanced

Taxes and market assumptions

Set taxes, returns and inflation. Set both volatility fields to 0% for deterministic market paths.

One-time cash flows

Add possible future lump sums such as inheritances, severance or other one-time payments.

Spending behavior

Set spending-smile behavior, inflation pauses after losses and cash reserves.

Housing offsets

Add mortgage payoff timing that can lower spending later in retirement.

Mortgages

Retirement mortgage assumptions table
MortgageYears remainingMonthly P&IAction

Social Security & pension offsets

Add claim timing and pension income that can lower portfolio withdrawals later.

Use this to include the possibility that benefits are reduced or unavailable by claim age. Some paths receive the full benefit; the rest use the reduced-benefit percentage.

Retirement healthcare

Compare bridge coverage paths before Medicare and ongoing Medicare-era assumptions.

Does annual retirement spending already include healthcare?

Included avoids double counting. Excluded adds the selected healthcare path to each retirement spending tier.

Bridge coverage path

Choose one bridge coverage path here. Medicare stays separate because it starts after the pre-Medicare years.

Simulation controls

Control run depth and use an optional seed for repeatable comparisons.

Savings contributions and spending targets start in today's dollars, then inflate path by path into nominal dollars. Expected nominal return is treated as an arithmetic average annual return, not a CAGR. The market model includes seeded random nominal returns, negative years, Student-t fat tails, sequence risk, random inflation and guardrail spending thresholds.

Mortgage P&I

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Mortgage Paid Off Around

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Social Security Starts Around

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Annual Social Security

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Retirement spending is assumed to already include active mortgage payments. As each mortgage pays off, the model reduces withdrawals by that row's monthly principal-and-interest amount, while Social Security reduces withdrawals once claimed. One-time payments are modeled as future cash inflows, treated as today's dollars inflated to the receipt year, included path-by-path using the configured probability, and can arrive earlier or later when timing variability is non-zero. The spending smile applies age-based multipliers to all three spend tiers before guardrails are chosen. Cash buffer is carved out of invested net worth into spendable cash, so it can still be used after risky investments hit $0.

Healthcare comparisons are modeled as planning assumptions only. They show estimated premium plus out-of-pocket ranges for pre-Medicare and Medicare-era coverage options so you can compare likely withdrawal pressure, not choose a specific plan.

Historical market replay

Historical replay uses one selected start year as the return and inflation path for the standard simulation output.

Populate the start year from a notable market window:

Children and dependents

No child/dependent assumptions saved yet.

Add one row per child or dependent, then add cost phases for expenses that start and stop at specific ages.

Scenario management

Scenario management

Saved retirement scenarios table
Saved scenariosSuccessMedian at retireRetirement ageGetting byNormalLife you wantExtraUpdated
No retirement scenarios saved yet.
Ready. The simulation uses seeded random returns and inflation, estimates the retirement balance, then compares flexible guardrails, fixed spending cases and named stress cases through age 100.