Retirement Simulator

Explore how savings, returns, inflation, taxes, passive income, Social Security, and spending assumptions change your retirement path. This is a fast planning tool for exploring retirement assumptions and tradeoffs.

Inputs

Timeline

Current age

Retirement age

End age

Portfolio

Current invested assets

Annual contribution before retirement

Nominal investment return (%) ?

Inflation (%) ?

Contribution growth (%)

Retirement Spending

Annual spending need in today's dollars

Passive income today

Passive income growth (%)

Social Security start age

Social Security income (today's dollars) ?

Taxes

Effective tax rate in retirement (%) ?

Passive income taxability (%) ?

Social Security taxability (%) ?

Spending input mode

Display

Show inflation-adjusted values in charts and outputs

Advanced

Safe withdrawal benchmark (%) ?

This version is deterministic. It does not run Monte Carlo simulations or model account types or changing asset allocation.

Portfolio at retirement

Inflation-adjusted

Retirement portfolio target

Based on safe withdrawal benchmark

Funding gap / surplus at retirement

Portfolio lasts until

—

Based on drawdown simulation

Portfolio at end of plan

$0 in today's dollars

Safe annual spending at retirement

Using safe withdrawal benchmark

Portfolio path

Solid line is the nominal portfolio. Dashed line is inflation-adjusted when enabled.

Cash flow at retirement

Shows after-tax spending target, taxes, income sources, and the remaining amount that must come from the portfolio. This will often look flatter in today's dollars if your assumptions are flat in today's dollars.

Selected checkpoints

Age	Portfolio	Inflation-adjusted	Portfolio withdrawal need

How to read the outputs

Portfolio at retirement is your projected nest egg when you stop contributing and start drawing down.
Retirement portfolio target is calculated from your after-tax spending target, grossed up for taxes, minus passive income and Social Security, then divided by the safe withdrawal benchmark.
Funding gap / surplus compares your projected portfolio to that target at retirement.
Portfolio lasts until comes from a simple year-by-year drawdown simulation with spending and income both growing over time. The cash-flow chart breaks this into total spending, taxes, passive income, Social Security, and the remaining portfolio draw.
Safe annual spending is your retirement portfolio multiplied by the safe withdrawal benchmark.
Use this tool directionally. Small changes to return, inflation, tax rate, spending, and retirement age can make a large difference.

What this tool does not model

Taxes beyond a simplified effective-rate model
Roth vs traditional accounts
Changing return assumptions over time
Sequence-of-returns risk / Monte Carlo
Healthcare and one-time shocks

This tool is designed to stay fast and easy to explore rather than model every retirement-planning detail.