Best FIRE calculators of 2026
7 FIRE calculators tested with the same case: 30-year-old, $100,000 saved, $60,000/year spending target, 50% savings rate. Two different jobs get conflated under 'FIRE calculator': accumulation math (when do I reach FI?) and withdrawal survival (will it last 50 years?). We ranked tools on which job they do well.
Quick comparison
| Tool | Free | No signup | Backtest | Savings rate | Coast FIRE | Chart | URL share |
|---|---|---|---|---|---|---|---|
| 1. Snowballr FIRE Calculator | ✓ | ✓ | — | ✓ | ✓ | ✓ | ✓ |
| 2. cFIREsim | ✓ | ✓ | ✓ | — | — | ✓ | — |
| 3. FIRECalc | ✓ | ✓ | ✓ | — | — | ✓ | — |
| 4. Networthify | ✓ | ✓ | — | ✓ | — | ✓ | ✓ |
| 5. Engaging Data FIRE Calculator | ✓ | ✓ | ✓ | ✓ | — | ✓ | — |
| 6. Empower Retirement Planner | ✓ | — | — | — | — | ✓ | — |
| 7. ProjectionLab | — | — | ✓ | ✓ | ✓ | ✓ | — |
Detailed reviews
Snowballr FIRE Calculator
Best overall for the full FIRE path with Lean/Coast/Barista variants
- 100% free, no sign-up, no email collection
- Full FIRE path: FI number, years to FI, savings-rate sensitivity
- Dedicated Lean FIRE, Fat FIRE, Coast FIRE, and Barista FIRE variants
- Visual chart with real (inflation-adjusted) framing
- URL-shareable scenarios
- Deterministic projections — no historical-cycle backtesting
- No account linking
cFIREsim
Best for historical-cycle backtesting of a retirement plan
- Simulates your plan through every historical market cycle since 1871
- Flexible spending models (Bernicke, variable percentage)
- Free and open about methodology
- Intimidating input screen for beginners
- No savings-phase guidance — assumes you know your numbers
- Occasional downtime (volunteer-maintained)
FIRECalc
Best for the classic success-rate question: will my money last?
- The original historical-cycle simulator
- Simple three-input start (spending, portfolio, years)
- Success rate across all starting years since 1871
- Dated interface
- Advanced tabs are easy to miss
- No savings-phase modeling
Networthify
Best for the savings-rate insight that drives the FIRE movement
- Shows years-to-retirement purely from savings rate — the core FIRE math
- Instant slider feedback
- Perfect for the 'save 50%, retire in ~17 years' realization
- Single-purpose — no withdrawal phase
- No inflation or tax nuance
- Long-unmaintained
Engaging Data FIRE Calculator
Best visualization of when work becomes optional
- Rich interactive charts including the 'rich, broke, or dead' framing
- Historical cycle success shading
- Longevity data overlay is uniquely sobering
- Chart density overwhelms some users
- Less flexible spending models than cFIREsim
- Ad-supported blog wrapper
Empower Retirement Planner
Best for FIRE tracking against real linked accounts
- Monte Carlo on your actual balances, updated automatically
- Spending goals and one-time events (college, house)
- Good for the accumulation years
- Requires sign-up and account linking
- Advisory sales calls at higher balances
- Not FIRE-native — early-retirement dates need workarounds
ProjectionLab
Best paid option for life-plan-level modeling
- Beautiful multi-decade plan modeling with life events
- Monte Carlo + historical backtesting both included
- Active development
- Meaningful features require the paid plan (~$9/month)
- Overkill for a first FI estimate
- Sign-up required to save
How we evaluated
Accumulation test: 30-year-old with $100,000 saved, spending $60,000/year (FI number $1.5M by the 4% rule), saving 50% of a $120,000 net income. At 7% real returns this reaches FI in roughly 13-14 years — tools using savings-rate math should land there. Withdrawal test: $1.5M portfolio, $60,000/year spending, 50-year horizon — historical backtesting tools should report a success rate near 80-90% at 4% withdrawal over 50 years (longer horizons are harsher than the classic 30-year Trinity result). Tools lost points for sign-up walls and for conflating the two jobs.
Verdict
Use two tools, one per job. For the accumulation question, Snowballr gives the FI number, timeline, and Coast/Barista variants instantly. For the withdrawal-survival question, cFIREsim is the standard — run your plan through every market since 1871 rather than trusting one average return. FIRECalc remains a fine simpler alternative, and Engaging Data adds the longevity overlay every early retiree should see once. If you want one paid tool to do everything, ProjectionLab is worth its subscription.
Frequently asked questions
What is the best free FIRE calculator?
For 'when do I reach financial independence', Snowballr or Networthify (savings-rate math, no sign-up). For 'will my portfolio survive early retirement', cFIREsim or FIRECalc (historical backtesting since 1871). Serious planners run both types — they answer different questions.
How long to reach FIRE at a 50% savings rate?
Roughly 15-17 years from zero at a 50% savings rate and 5-7% real returns — the classic Mr. Money Mustache 'shockingly simple math' result. Starting with $100,000 already saved on a $60,000/year spending target cuts it to about 13-14 years.
Is the 4% rule safe for early retirement?
Over the classic 30-year horizon the 4% rule survived about 95% of historical periods. Over 50-year early-retirement horizons, historical success drops to roughly 80-90%, which is why many FIRE plans use 3.25-3.75% withdrawal rates or build in flexibility to cut spending in bad markets.