The Universal Calculation Engine
The Universal Calculation Engine
Retirement Calculators

Use these calculators to plan wealth, retirement, and debt payoff. Start Here with Wealth Builder and the 401(k) growth simulator. Plan Your Future with Retirement Architect. Reality Check includes the 4% rule, FIRE calculator, savings rate, net worth benchmark, FI progress, and retirement readiness score. Live on Your Money covers retirement income, withdrawals & longevity, and Social Security break-even. Big Financial Decisions links to home affordability, mortgage, rent vs buy, and HELOC. Stability & Risk uses the Debt Destroyer. Grow & Deploy Capital opens the ROI & Business Analyzer. Advanced includes Compare Strategies. Search or pick a category below to start.

Tools by category

WEALTH BUILDER
Start here: project future balance from savings, contributions, growth presets, fees, and charts (shared assumptions).
Starting point
Horizon
Growth style

Presets use Expected return and Market benchmark from Adjust Assumptions (Custom uses the field below).

Advanced (fees)

Inflation and tax drag come from ⚙️ Adjust Assumptions above.

Portfolio growth (principal vs growth)
Growth vs contributions
Portfolio value over time
Milestones

Retirement Architect — terms

Definitions for inputs, Advanced Planner fields, optimizer sections (tradeoffs, stress test, recommendations, strategies), and results.

Expected return
Nominal annual investment return you assume before inflation. It drives portfolio growth in the accumulation phase.
Inflation
Annual inflation rate used to translate between nominal dollars and real (purchasing-power) outcomes.
Tax drag
Percentage points subtracted from expected return to approximate taxes and other frictions on growth (not a tax bracket; a simple drag on the rate).
Market benchmark
Return assumption for the comparison (“benchmark”) path on the growth chart. It does not change your plan math unless you use it as a reference line.
Safe withdrawal rate (SWR)
Percentage of your portfolio you plan to withdraw in the first year of retirement (e.g. 4%). Used with spending needs to estimate how large a portfolio must be.
Life expectancy (age)
Last age included in the retirement spending and drawdown projection (longevity horizon).
Retirement age
Age at which you stop working and begin drawing from the portfolio under this plan.
Desired monthly income
Target pretax monthly spending in retirement when not using the replacement-ratio method.
Replacement ratio
Percentage of your pre-retirement income you want to replace in retirement. Used only when “Use replacement ratio” is enabled.
Buffer
Extra monthly dollars added on top of your income target as a cushion.
Simple vs Advanced planner
Simple mode uses total current savings and one monthly contribution. Advanced mode splits balances and contributions across 401(k), Roth IRA, traditional IRA, taxable, and other accounts, with optional employer match, growth rates, and catch-up.
Account balances & contributions (Advanced)
Each bucket has its own balance and monthly employee contribution. The engine rolls them into one accumulation path; total savings and total contributions shown are derived from these fields.
Employer match (% of deferral / % of salary)
Match is modeled as extra dollars to the 401(k): a percentage of your deferral, optionally capped as a percentage of salary. It increases effective savings but follows the simplified rules shown in the form.
Contribution growth (%/yr)
Annual percentage increase applied to employee contributions over time in Advanced mode (e.g. raises or auto-escalation).
Salary growth (%/yr)
Annual growth rate for salary used when match limits depend on salary or when scaling income-based fields.
Catch-up ($/mo)
Optional extra monthly deferral when catch-up is enabled (simplified stand-in for age-50+ additional contributions).
Social Security (% of income)
Estimated Social Security as a percentage of pre-retirement income, used to reduce how much must come from the portfolio.
Social Security claim age
Age at which you begin benefits (62–70 in this model). Before that age in retirement, Social Security is treated as $0; from that age on, the modeled benefit applies and grows with inflation each year.
Pension
Fixed monthly pension income in retirement (not inflation-adjusted in this simplified model unless noted).
Maintenance reserve
Annual housing maintenance allowance as a percentage of income (via the engine’s housing proxy).
Property tax
Annual property tax rate applied to the housing cost proxy (see the note under the inputs).
Insurance ($/yr)
Annual homeowners insurance included in expense load alongside maintenance and property tax.
Monte Carlo
Optional simulation that runs many random return paths to estimate success rates and ending balances.
Trials
Number of Monte Carlo paths run; more trials give smoother statistics but take longer to compute.
Volatility (% annual)
Standard deviation of annual returns used to randomize paths in Monte Carlo (spread of outcomes).
Sequence-of-returns stress
When enabled, stresses early-retirement returns to approximate sequence-of-returns risk (bad markets right when withdrawals start).
Tradeoff explorer
Sliders for retirement age, monthly contribution, and desired spending to preview readiness, FI age, and (after load) Monte Carlo success without changing your main plan until you choose Sync from plan.
Stress test
Checkboxes that layer adverse assumptions (e.g. crash-style path, lower returns, longer life, higher inflation). Stressed success rate uses the same Monte Carlo settings with those overlays applied.
Recommended actions
A short list of changes ranked by estimated impact on Monte Carlo success rate versus your current plan, with a brief rationale for each.
Strategy comparison
Save snapshots of your inputs for this session and compare Monte Carlo success, FI age, and readiness in a table. Saved plans are not stored after refresh.
Preset scenarios (engine)
Conservative, base, and aggressive presets adjust return, inflation, SWR, and maintenance assumptions so you can compare deterministic projections side by side.
Insights
Plain-language notes from sensitivity-style passes on the same engine (e.g. inflation, contributions, retirement age) plus context when Monte Carlo results are available.
Portfolio needed
Estimated nest egg required at retirement to support your spending and withdrawal rule, net of other income sources.
Projected at retirement
Estimated portfolio balance at your retirement age given contributions and return assumptions.
Readiness
Ratio of projected balance to required balance (how close you are to the stated goal).
Years to goal / FI age
Approximate years until the projected balance meets the required portfolio, and the implied financial-independence age when applicable.
First-year withdrawal
Portfolio-funded spending needed in the first retirement year after Social Security and pension.
MC success
Share of Monte Carlo trials where the plan did not deplete under the simulated paths (when Monte Carlo is enabled).
Diagnostics
Summary of net nominal return, real return, gap vs benchmark at retirement, and annual housing-related costs used in the model.
RETIREMENT ARCHITECT
Plan your future: when you can stop working, portfolio vs benchmark, income mix, KPIs, optional Monte Carlo; Simple or Advanced savings detail.
Planning mode
Return assumptions

Nominal return before inflation. Tax drag is percentage points subtracted from expected return (net effective return). Benchmark drives the comparison path only.

Withdrawal & longevity
Lifestyle target
Current position
Safety nets & expense load

Property tax uses a housing proxy: annual property tax ≈ 25% of income × property tax rate (see engine constants).

Monte Carlo simulation
Portfolio needed
$3,244,750
Projected at retirement
$1,063,175
Readiness
33%
Years to goal / FI age
First-year withdrawal
$129,790
MC success
Plan summary

With these assumptions, the required portfolio is $3,244,750. Your projected balance at retirement is $1,063,175. You may not reach the goal before the retirement age you set. Consider higher contributions, a later retirement age, or lower spending. Effective net return (nominal minus tax drag) is about 5.50% per year before inflation. Readiness compares your projected balance to the portfolio implied by your withdrawal rule, currently about 33%.

Tradeoff explorer

Explore retirement age, savings rate, and spending without changing your saved inputs. Use "Sync from plan" to reset sliders.

Preview readiness 33% · Projected at retirement $1,063,175 · FI ~
Stress test

Layer adverse assumptions; success rate recomputes with the same Monte Carlo engine (crash = higher volatility + sequence-of-returns ordering).

Strategy comparison

Save the current inputs as a named strategy and compare success rate, FI age, and readiness across scenarios you care about.

Preset scenarios (engine)
ScenarioProjectedRequiredYrs to goalReadiness
conservative$650,162$4,929,11813%
base$1,063,175$3,244,75033%
aggressive$1,656,318$2,762,35360%
Charts
Accumulation vs benchmark
Contributions vs growth
Income sources (first year)
Retirement drawdown
Insights
  • Raising inflation by 1 point would move readiness about -10% (portfolio need vs. projection).
  • Adding about $100/month to contributions moves readiness by roughly +3% under the same return assumptions.
  • Tax drag trims nominal return from 7.0% to an effective 5.5% before real growth.
  • Versus the benchmark path, you end up behind by about $2,309,390 at retirement.
  • Readiness is below 85% of the required portfolio — consider raising contributions or delaying retirement.
Diagnostics
Net nominal 5.50% · Real return 2.50% · Δ vs benchmark -$2,309,390
Property tax / yr $240 · Maintenance reserve / yr $1,545 · Insurance / yr $1,500
Cumulative contributions to retirement $192,000 · Growth from investments $771,175
DEBT DESTROYER
Stability and risk: avalanche or snowball with extra payments, payoff timeline, and interest vs principal.
Debts
NameBalance ($)APR (%)Min. payment ($)
Debt balance over time
Interest vs principal
ROI & BUSINESS ANALYZER
Grow and deploy capital: return vs benchmark from initial stake, ending value, years held, and ongoing costs.
COMPARE STRATEGIES
Advanced decision engine: compare invest vs pay debt, real estate vs stocks, and retirement age paths with recommendations, confidence, break-even thresholds, and scenario robustness.
Comparison type

Investment return uses Expected return (%) from ⚙️ Adjust Assumptions (minus tax drag).

Extra $ each month
401(k) Growth Simulator
Start here: project one 401(k)-style account to retirement with match, salary growth, contributions, and inflation.
Balance Over Time
Retirement Income Planner
Live on your money: stack Social Security, pension, annuities, and other income vs your target; optional scenarios.
Total retirement income/ month
Status
Annual
Lifetime (to age)
Income vs target
Monthly income by source
Income over time (by age)
Social Security: benefit by claim age (62–70)
Scenario comparison

Add current inputs as a scenario to compare (e.g. SS at 62 vs 70).

Withdrawal & Longevity Planner
Live on your money: withdrawals, RMDs, tax-aware order, and whether balances last through life expectancy.
Age money runs out
Monthly income supported
Years supported
Total lifetime withdrawals
Balance at life expectancy
RMD impact
Longevity
Portfolio balance over time
Planned withdrawal vs RMD
Annual withdrawal
Account depletion (order: Taxable → Traditional → Roth)
Spending taxable first preserves tax-advantaged growth. Roth last gives most flexibility.
Scenario comparison

Add current inputs as a scenario (e.g. lower withdrawal vs higher).

4% Rule Calculator
Reality check: safe annual and monthly withdrawal from a balance and adjustable rate; sustainability and longevity.
FIRE Calculator
Reality check: years to financial independence from savings rate, income, spending, returns, inflation, and withdrawal rate.
Savings Rate Calculator
Reality check: savings rate from annual income and annual savings with a simple band label (educational heuristic).
Net Worth Benchmark
Reality check: compare net worth to an age-based expected level (income multiple or fallback curve) with a rough percentile band.
Financial Independence Progress
Reality check: progress toward a 25× annual-expenses financial independence target from current net worth.
Retirement Readiness Score
Reality check: projected savings at retirement vs an income-based target using growth and ongoing contributions (heuristic score 0–100).
Social Security Break-Even Calculator
Live on your money: compare claiming ages and cumulative lifetime Social Security benefits.

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