FIRE calculators / retirement planning / choosing a tool
Which FIRE calculator should I use?
There is no single best FIRE calculator. Use a simple calculator for a quick retirement number, FIRECalc or cFIREsim to see whether a spending plan survived past market conditions, ProjectionLab or Boldin for taxes, income and life changes, and FIRE Decision Lab to compare what your retirement portfolio should own.
Pick the calculator that answers your next decision.
A tool can be excellent and still be wrong for the question in front of you. Start with the smallest tool that answers that question clearly. Use another when the question changes.
Enter your amount and monthly spending. The free planner compares the same goal across 24 tested portfolio approaches and gives you three clearly different choices.
01 / The quick comparison
Start with the question you need answered.
| Your question | Use this kind of tool | Good place to start |
|---|---|---|
| How much might I need? | Quick FIRE number | Monthly spending table |
| Would my spending have lasted? | Historical retirement test | FIRECalc or cFIREsim |
| How do taxes and life changes fit? | Detailed financial plan | ProjectionLab or Boldin |
| What should the portfolio own? | Portfolio comparison | FIRE Decision Lab |
Do not choose by the longest feature list. Choose by the decision you are trying to make.
02 / Test whether the money lasts
Use FIRECalc or cFIREsim for historical retirement survival.
Both tools replay a portfolio and spending plan across many past market periods. That helps answer whether the plan would have run out of money during the historical periods they test. FIRECalc also lets you change spending, other income, retirement timing, fees and the stock-and-bond mix. cFIREsim offers several spending rules and detailed portfolio adjustments.
03 / Model the rest of your life
Use ProjectionLab or Boldin for a detailed financial plan.
These tools are built for more moving parts: income, expenses, accounts, taxes, Social Security, future goals and “what if” changes. ProjectionLab offers basic retirement projections for free and reserves advanced tax, cash-flow and withdrawal features for paid plans. Boldin has a free starting plan with paid planning features available.
04 / Compare what to invest in
Use FIRE Decision Lab when the unanswered question is what your retirement portfolio should own.
Many calculators start with one stock-and-bond mix or ask you to choose the mix yourself. FIRE Decision Lab keeps your money, spending and retirement length fixed while comparing 24 tested portfolio approaches. It then shows three choices: the most reliable, the best balance of reliability and growth, and the most growth among the approaches that cleared its reliability floor.
It is deliberately narrower than a complete tax or cash-flow planner. It does not model every account or tell you that one portfolio is personally suitable.
Compare portfolios for my retirementSources and limits
Check what each calculator actually answers.
Why these tools appear here
The descriptions come from each tool's own current public documentation. FIRE Decision Lab is our tool. The other tools are not paid or affiliated recommendations, and their features and prices can change.
What no calculator can prove
No calculator can predict future returns, inflation, tax law or your future spending. Historical tests show how stated rules behaved in the periods and assets tested. Forecasts depend on assumptions. Neither is a guarantee or personal financial advice.
Official sources
Read the current descriptions directly from FIRECalc, cFIREsim, ProjectionLab, and Boldin.
Use this result
See how much you need to retire—and compare what to invest in.
Enter what you have and what you want to spend each month. Compare three portfolios against the same market history. Your financial figures stay in your browser.
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