Retirement Savings Gap and FIRE Calculator
Compare projected retirement savings with a portfolio target based on spending, healthcare, benefits and taxes. The calculator models your selected retirement age alongside earlier and later scenarios. All assumptions are editable, including inflation and investment return, so you can see how a different retirement date changes the savings gap and monthly contribution needed.
Your scenario
Enter your own numbers or load the worked example. Values are calculated in this browser and are not saved.
Your estimate
Complete the scenario to see a result, its breakdown and limitations.
Monthly amortization schedule
| Month | Payment | Interest | Principal | Balance |
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Next steps
Check the assumptions with your records before making a decision. Related calculators can help compare the next part of your plan.
How the estimate works
Grow current savings and end-of-month contributions at the assumed investment return. Inflate the spending gap to each retirement age, gross it up for withdrawal taxes, and divide by the selected withdrawal rate to obtain a target portfolio.
Worked example
With a $40,000 annual portfolio-funded spending gap, zero withdrawal tax and a 4% withdrawal rate, the target is $1 million in today’s dollars before inflation.
Sources and review scope
Source comparison: 2026-09-23. Methodology owner: Toolistify. Implementation reviewed through automated source checks and regression tests; this is not professional tax, legal, benefits or financial certification.
Calculation inputs stay in this page; CSV downloads are created locally. The optional sales-tax lookup has separate disclosure above. Privacy · Corrections
Questions and answers
Is 4% guaranteed to last?
No. Withdrawal rates and investment returns are assumptions, not guarantees. Volatility and the order of returns can materially change outcomes.
Are the scenario amounts in today’s dollars?
Spending inputs are in today’s dollars; projected balances and targets at retirement are nominal future dollars.