Retirement Planner — Start Here

Retirement Planner
Complete retirement picture

Can this household fund retirement?

The deterministic base case comes first, followed by stress tests, Monte Carlo and spending capacity.

Beginning portfolio ?
$5.00M
Ver. 26.1 test household
Annual spending
$215K
4.30% of starting portfolio, before income taxes
Base-case projected legacy
$2.04M
PV $755K • portfolio never depleted
90% MC spending level
$196K
$19K below current spending

Base Case

3.29%
After-tax nominal CAGR • 0.04% real CAGR

Lost Decade

2.87%
After-tax nominal CAGR • −0.37% real CAGR

Poor Start / Sequence Risk

2.46%
After-tax nominal CAGR • −0.58% real CAGR
Deterministic spending capacity
$240.3K
Base-case cushion +$25.3K / +11.8%
Start here

See how well your retirement plan can handle an uncertain future.

RetireByPlan combines a Base Case, historical and deterministic stress tests, Monte Carlo analysis and Spending Capacity to help you understand the range of outcomes your plan may face.

Will my money last?
What range of outcomes should I prepare for?
What if retirement doesn’t go as planned?
How much spending can my resources support?
The goal isn’t to predict one future. It’s to understand how many different futures your retirement plan can tolerate.

Guide Me Step by Step

Work through the key assumptions one at a time. Each question includes a short explanation, while the planner updates the same underlying inputs used everywhere else.

Interactive Guided Setup

Ask RetireByPlan helps you navigate each input section and explains what information is needed. Your inputs remain under your control.

Enter Inputs on My Own

Go directly to the complete input screens. This is best if you already know the assumptions you want to use or want to review every available setting.

All three approaches use the same retirement model. Guided entry does not simplify the calculation engine. Advanced assumptions begin with the RetireByPlan Defaults and remain available on the full Inputs screens.
ADD OR EDIT OPTIONAL ITEMS
Jump to an optional section at any time. When finished, select “Return to previous question” to resume where you left off.
Free planner

Retirement Planning Inputs

Enter or revise the assumptions used by the retirement plan. Dollar amounts are shown as whole dollars; rates are shown as percentages or basis points.

Base Case: The assumptions currently entered are the Base Case being analyzed. Save as My Base Case stores those assumptions on this browser/device so you can return to them later. Reset to My Base Case restores your saved assumptions. Reset to RetireByPlan Defaults restores the app’s original starting assumptions.

Personal assumptions

Primary tax assumptions

Spending assumptions

Monthly equivalent: $10,417

Spending changes by age ?

One-time future income & expenses — after tax, future dollars ?

DescriptionAmountAge
Enter expenses as negative dollar amounts and income or proceeds as positive dollar amounts.

Employment & Retirement Status

Independent of your own retirement status. Requires spouse age and life expectancy.

Effective Tax Rate on Retirement Income Other Than Investment Income

What this rate represents: Applies to recurring other ordinary income, pension and annuity income, and the taxable portion of Social Security. Current job/business income uses its own employment tax rate. Investment income and portfolio returns are handled separately through the Effective Annual Investment Tax Drag assumption, which is shown on the Investment Portfolio Assumptions tab above.

Earned / Other Income ?

DescriptionAnnual amountBeginning ageEnding ageInflation adjustment

Pension / Annuity Income

DescriptionAnnual pension / annuity amountBeginning agePayments endEnding age
Convention: Pension and annuity amounts are nominal dollars at the age payments begin. They remain fixed unless inflation adjustment is selected. Payments can end at the user's modeled death, spouse's modeled death, last death, or a specified age.

Social Security ?

Today’s dollars; modeled inflation applies before and after claiming.
Today’s dollars; modeled inflation applies before and after claiming.

Portfolio & economic assumptions

How return and volatility work in the Base Case: Annual Portfolio Return is an arithmetic return assumption before investment costs, taxes, and volatility drag. Even though the Base Case is deterministic rather than a Monte Carlo simulation, a portfolio with variable annual returns generally compounds at a lower rate than its arithmetic average. The model estimates this volatility drag as 0.458 × annual volatility² and subtracts it when estimating the Base Case compound return. Monte Carlo uses the same volatility input differently: it creates variation around the return assumption across the 1,500 simulated paths. Volatility drag is not a fee or cash expense; it is a mathematical compounding adjustment.

Investment portfolio tax assumptions

Definition: Annual reduction in investment returns attributable to taxes, expressed as a blended planning assumption rather than a tax rate on the entire portfolio.
Definition: Used only when a Monte Carlo simulation produces a negative investment return. It estimates how much of the potential tax benefit from an investment loss can actually be used. A 50% factor assumes half of the theoretical tax benefit is realized, recognizing limits from the timing of gains, loss carryforwards, tax rates and the ability to use losses when they occur. It does not affect the deterministic Base Case when the assumed annual investment return is positive.
Definition: Unrealized taxable gains already built into the taxable portfolio today.
Definition: Percentage of today’s embedded taxable gains expected to be realized during the planning horizon. The realized-gain amount is multiplied by the Effective Annual Investment Tax Drag, and the resulting modeled tax cost is spread evenly across the planning years.
Definition: The model applies this percentage each year to the investment portfolio’s market value above the Portfolio Exempt from Wealth Tax amount, beginning with the annual period that starts at the entered age.
Your current Base Case assumptions

Plan Overview

Before reviewing results, confirm that this is the retirement plan you intended RetireByPlan to analyze.

Household & horizon ?
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—
Beginning portfolio
—
Investment portfolio modeled
Starting annual spending
—
—
Return / volatility
—
— ?

Your plan in plain English

Retirement income

Future changes & one-time cash flows

Investment costs & tax assumptions ?

✓ These are the Base Case assumptions RetireByPlan will analyze on the following results pages.
Deterministic analysis

Base Case Retirement Projection

Base Case Assumptions

Uses the assumptions currently entered in Retirement Inputs.

These are the current Base Case assumptions used for the deterministic projection below.

Base Case Results

Portfolio depleted? ?
Never
Projected legacy ?
—
Future dollars at end of planning horizon
Present value of legacy ?
—
—
Starting spending including income taxes ?
—
—

Base Case Return Calculation

Arithmetic portfolio return before costs—
Estimated volatility drag ?—
Estimated compound return before costs (CAGR) ?—
After annual fund expense ?—
After investment tax drag, before advisor fee ?—
After all investment costs, investment tax drag & advisor fee ?—
Approx. real return before average-balance fee adjustment ?—
CAGR (Compound Annual Growth Rate): the single constant annual return that would produce the same compounded growth as a sequence of varying annual returns. Unlike an arithmetic average, CAGR reflects the effect of compounding. The estimated compound return before costs above is the Base Case CAGR estimate before investment costs and tax drag.
Reading this calculation: Volatility drag is a compounding adjustment, not an investment expense. Fund expenses reduce return before the investment tax-drag calculation; advisor fees are then deducted separately. The model also makes a small year-by-year fee adjustment so annual fund expenses and advisor fees approximate charges based on the average invested portfolio value during each year. Because that adjustment depends on each year’s beginning and ending invested portfolio value, it is not represented as one fixed annual return percentage.

Lifetime Values & Costs ?

Total lifetime after-tax Social Security ?—
Present value of lifetime after-tax Social Security ?—
Total investment fund expenses—
Present value of investment fund expenses—
Present value of fund expenses as % of beginning portfolio—
Total advisor fees—
Present value of advisor fees—
Present value of advisor fees as % of beginning portfolio—
Total investment & advisor costs—
Present value of total investment & advisor costs—
Present value of total costs as % of beginning portfolio —
Present value: Each future annual amount is discounted back to today using the entered Annual Inflation rate. Fund-expense totals are shown at their stated gross expense rate; their impact on portfolio returns retains the model’s investment-tax-drag treatment. Advisor fees are not tax-adjusted. End-of-period one-time cash flows are excluded from that year’s average fee base.
Deterministic Stress Testing Scenarios

Deterministic Stress Testing Scenarios

Base Case Assumptions

Uses the assumptions currently entered in Retirement Inputs.

These are the current Base Case assumptions used as the starting point for the stress scenarios below.

Choose Return & Inflation Scenario

Portfolio Allocation for Historical Scenarios

Used for Depression Early Years, Depression Later Years, High Inflation and Pandemic. Historical inflation stays unchanged; the five annual portfolio returns are recalculated from the selected allocation.

Total: 100%

Historical asset-return and inflation source: Aswath Damodaran, NYU Stern, Historical Returns on Stocks, Bonds and Bills: 1928–2024. Portfolio returns are annual weighted nominal total returns using S&P 500 total return, 10-year U.S. Treasury bond return, gold, and 3-month T-bills, rebalanced annually.

Historical scenarios use both historical returns and historical inflation. Inflation changes modeled spending and inflation-linked Social Security during the historical period. A deflationary episode can therefore reduce future spending enough that a scenario with poor nominal investment returns can still finish with a higher nominal legacy than the Base Case. Compare both the return CAGR and inflation CAGR when interpreting these results.
What CAGR means: CAGR (Compound Annual Growth Rate) is the single constant annual rate that would produce the same cumulative result as the actual sequence of annual changes over the period. It is not the arithmetic average. For investment returns, CAGR shows the constant annual return equivalent to the compounded five-year return sequence. For inflation, it shows the constant annual inflation or deflation rate equivalent to the cumulative change in the price level over the same period.

Stress Test Results

Selected Scenario

Portfolio depleted? ?
—
Projected legacy ?
—
Future dollars

Base Case — Same Current Inputs

Portfolio depleted?
—
Projected legacy
—
—
5-year gross return CAGR ?
—
Before investment costs and investment taxes
5-year after-tax & investment-cost CAGR ?
—
Investment return statistic; excludes household cash flows
5-year inflation CAGR ?
—
Equivalent compounded annual inflation or deflation

Selected Five-Year Return & Inflation Path

YearGross portfolio return ?Inflation

Stress Result

Starting spending—
Ending portfolio—
Present value of ending portfolio—
Present value of ending portfolio as % of beginning portfolio ?—
Selected scenario—
Historical allocation—
For historical scenarios, the selected five-year gross return and inflation sequence is applied first; after year five, the model returns to the normal base-case return and inflation assumptions.
Probabilistic analysis

Monte Carlo — 1,500 Market Scenarios

Monte Carlo is an important second lens, not the only retirement result.

Base Case Assumptions

Uses the assumptions currently entered in Retirement Inputs.

These are the current Base Case assumptions used as the starting point for the Monte Carlo analysis. Monte Carlo also uses the Investment Loss Benefit Factor when a simulated annual return is negative.

1,500 Monte Carlo Portfolio Paths

Optional visualization of the same 1,500 stochastic market scenarios used by the Monte Carlo model.
Depleted before horizonFunded, ending below starting portfolioFunded, ending at or above starting portfolioMedian ending legacy
Technical details: highest simulated paths
The graph is display-only. It does not alter the Monte Carlo calculations or assumptions.

Monte Carlo Results

1,500 Market Scenarios

Annual shocks are normally distributed around the expected arithmetic portfolio return using the portfolio volatility assumption. About 68% of normal observations lie within ±1 standard deviation, about 95% within ±2, and about 99.7% within ±3. The same 1,500 shock paths are reused when assumptions change.

Gross portfolio return CAGR across the Monte Carlo paths: These CAGRs compound each path’s simulated annual portfolio returns over the full planning horizon before fund expenses, advisor fees, investment tax drag, spending, income, or other household cash flows. They describe the investment-return paths themselves—not the CAGR of the ending legacy.
10th percentile CAGR ?
—
Median CAGR ?
—
Average path CAGR ?
—
90th percentile CAGR ?
—
Paths funding full horizon
73.9%
Median legacy
—
—
Average legacy
—
—
90th percentile legacy
—
—

What the distribution says

10th percentile ?$0
Median ?—
Average ?—
90th percentile ?—
90%-funded starting spending ?—
Current-spending cushion vs 90% ?—
The model uses the same 1,500-scenario sample on each calculation, validated against a larger 50,000-path sample, so changing an input can be compared against the same underlying stochastic market scenarios rather than a newly drawn sample. The 1,500 paths are a representative random sample of the model’s assumed normally distributed annual return shocks, preserving the expected center and dispersion of that distribution.

Legacy distribution

Distribution of ending portfolio values across all 1,500 modeled scenarios. Vertical markers identify the 10th percentile, median, average and 90th percentile ending legacy.
Retirement plan sensitivity analysis

Base Case Sensitivity Analysis

How sensitive is your Base Case?

See your current Base Case and explore how much the result changes when one important assumption differs from your plan.

Your Base Case uses the assumptions currently entered in Retirement Inputs. “Save as My Base Case” lets you save those assumptions so you can return to them later. Sensitivity tests do not change your current inputs or your saved My Base Case. Each slider temporarily changes only the assumption shown while every other current input remains constant. The slider ranges are intended to test plausible adverse and favorable outcomes, not to recommend assumptions.

Your Plan at a Glance

Starting portfolio
—
Current annual spending
—
Base Case ending portfolio
—
—
Base Case portfolio depleted?
—
—
How to use the sliders: Explore the full plausible ranges below. Move one assumption at a time; the dark marker shows your current Base Case assumption.

How sensitive is your Base Case?

Move one slider at a time. The dark marker shows your current Base Case assumption.

What Matters Most to Your Plan?

How this ranking differs from the sliders: The ranking uses a separate set of standardized adverse tests so the assumptions can be compared more consistently.

Each assumption is changed by the standardized adverse test shown below while all other Base Case inputs remain unchanged. The list is ranked by the reduction in ending portfolio value.

RankAssumptionBase CaseStandardized adverse testTest resultEnding portfolio change vs Base Case ?Relative importance

Sensitivity Range — Tornado View

This chart uses the full low-to-high range of each interactive slider, shown beside each assumption below. Each assumption is changed individually while the others remain at the Base Case. The bars show the resulting change in ending portfolio value; this is separate from the standardized adverse ranking test above.

Stress Test Snapshot

A compact view of selected deterministic stress tests using the same stress-test engine as the full Stress Tests page.

Monte Carlo Snapshot

The same 1,500 modeled market paths used on the Monte Carlo page.

Paths funding full horizon
—
10th percentile legacy
—
—
Median legacy
—
—
90th percentile legacy
—
—

Spending Flexibility

Compare current starting spending with the estimated starting spending level at which at least 90% of the 1,500 modeled paths remain funded through the planning horizon.

Current annual spending
—
90%-funded starting spending
—
Modeled spending cushion
—
—

Overall Interpretation

    These observations describe the model results under the assumptions entered. They are not a guarantee of future outcomes or a recommendation to maximize spending.
    Year-by-year detail

    Graphs & Tables

    See how spending, retirement income, portfolio cash flows and portfolio value change through the Base Case planning horizon.

    Base Case audit view: These graphs and the table below are generated from the same current inputs and Base Case calculation logic used elsewhere in the planner. Dollar values are nominal future dollars unless specifically labeled present value.

    Portfolio Balance by Year

    Ending investment portfolio value through the planning horizon. Hover over the line to see the exact year and amount.

    Annual Spending & Retirement Income

    Side-by-side annual bars compare modeled household spending with after-tax recurring retirement income. Hover over a year to see exact amounts and any identifiable cause of a material change.

    Net Portfolio Cash Flow by Year

    One bar per year shows cash added to or withdrawn from the portfolio before investment growth. Hover over a year for the exact amount, underlying components and identifiable changes.

    Year-by-Year Base Case Cash Flow Table

    Scroll horizontally to see the complete annual detail. The Excel download includes this table, the current assumptions and a summary of key Base Case results.

    Decision-oriented outputs

    Spending Capacity & Safety Cushions

    Translate return and inflation assumptions into amounts a retiree can act on.

    Base Case Assumptions

    Uses the assumptions currently entered in Retirement Inputs.

    These are the current Base Case assumptions used as the starting point for the spending-capacity analysis below.

    Spending Capacity Results

    Base Case ?

    —
    Maximum starting spending
    Current spending—
    Dollar cushion—
    Percent cushion—

    Lost Decade ?

    —
    Maximum starting spending
    Dollar cushion—
    Percent cushion—

    90% Monte Carlo ?

    —
    Maximum starting spending
    Dollar cushion—
    Percent cushion—
    Return and inflation cushions are Base Case sensitivity tests. Each changes only one assumption at a time while holding every other current input constant. The return cushion does not simultaneously change inflation, and the inflation cushion does not simultaneously change portfolio return.

    Return cushion ?

    —
    Minimum portfolio return required to fund full horizon
    Current assumed return—
    Return cushion—

    Inflation cushion ?

    —
    Maximum inflation that funds the full horizon
    Current inflation—
    Inflation cushion—
    Premium module

    Adaptive Retirement Portfolio

    Replace generic portfolio assumptions with portfolio-specific expected return, volatility, income yield and investment costs.

    Premium
    Normalized net return
    5.74%
    Planning volatility
    8.5%
    Income yield
    3.29%
    Capital appreciation
    2.45%

    How it feeds the free planner

    The paid ARP module can pass return, volatility, normalized income yield, weighted fund expenses and adviser fee into the central Retirement Planner. That eliminates duplicate entry while keeping the planner usable for free users who enter their own assumptions.

    Premium module

    Portfolio Tax Drag

    Future Ver. 27 architecture separates income, appreciation and loss-tax benefits.

    Premium
    PAID

    Income taxation

    Portfolio-specific treatment of interest, municipal income and dividends.

    PAID

    Appreciation taxation

    Realization and deferral rather than taxing all appreciation annually.

    PAID

    Loss Benefit Factor

    Apply potential tax value only to negative capital appreciation.

    For this Ver. 26.1 demonstration, the existing 28% effective annual investment tax-drag input remains in the core model. The richer tax architecture is intentionally shown as a future paid integration.
    Premium module

    Roth Planning

    Two specialized modules feed economic outputs back to the central retirement plan.

    Premium
    PAID

    Roth Conversion Decision Model

    Compare taxable, Traditional IRA, conversion-to-Roth and existing Roth wealth on a consistent economic basis.

    PAID

    Roth Conversion Tax Planner

    Model annual conversion headroom, brackets, NIIT, Social Security taxation, state tax and IRMAA.