5 Free Chrome Extensions Every Early Retiree Needs (2026)
A walkthrough of 5 free Chrome extensions for early-retirement / FIRE planning — built by the QuantCalc team, all free, all run locally in the browser, no signup. Each covers one slice of the planning workflow: Monte Carlo simulation, plan stress-testing, Roth conversion, RMDs, and FIRE shape (Coast/Barista/Lean).
The shortlist
For early retirement / FIRE planning specifically, you need five capabilities: (1) Monte Carlo simulation, (2) Roth conversion modeling, (3) RMD projection, (4) tax-aware withdrawal planning, and (5) ACA subsidy cliff visibility. Each of these has a single Chrome extension that handles it cleanly without trying to sell you a subscription.
The 5 worth installing
- Monte Carlo Retirement Calculator — full plan-from-scratch tool
- Monte Carlo Portfolio Stress Tester — stress-test a plan you already have
- Roth Conversion Calculator 2026 — multi-year conversion math
- RMD Calculator 2026 — Uniform/Joint Life RMDs
- FIRE Calculator — Coast/Barista/Lean FIRE numbers
All five run locally in your browser — no data leaves your machine, no signup. The methodology behind each tool is documented in its popup and on quantcalc.app/methodology.html.
Quick comparison
| Extension | Monte Carlo | Multi-year | Tax-aware | Free tier |
|---|---|---|---|---|
| Monte Carlo Retirement Calculator | ✓ 100 paths | ✓ to age 120 | basic | no PRO tier |
| MC Portfolio Stress Tester | ✓ 100 paths | ✓ to age 120 | no | PRO $4.99 |
| Roth Conversion Calculator | single-year | ✓ 30y horizon | ✓ federal | PRO $4.99 |
| RMD Calculator 2026 | deterministic | ✓ 10y proj | basic | PRO $4.99 |
| FIRE Calculator | deterministic | ✓ to FIRE age | no | PRO $4.99 |
The deeper picks
1. Monte Carlo Retirement Calculator
This is the one I'd install first if you're building a retirement plan from scratch. Takes your inputs (age, savings, contribution, withdrawal, allocation, inflation) and runs 100 Monte Carlo simulations using a real lognormal-return model with correlated 5-asset returns. Picks between JPMorgan LTCMA 2026 and Historical 1926-2025 forecasts. Shows success rate plus P10/P25/P50/P75/P90 ending balances plus a fan chart.
The output is the actual range of outcomes — the bad case (P10), the median, the good case (P90) — under realistic market uncertainty, instead of a single number. Same math as the QuantCalc web app (free), so if you want to graduate to 10,000 paths plus tax modeling later, the inputs transfer cleanly.
2. Monte Carlo Portfolio Stress Tester
Different use case from the planner above: this one assumes you already have a plan and want to know how it survives bad markets. Same 100-path simulation, but the inputs are framed around portfolio value, drawdown tolerance, and time horizon — not contribution/withdrawal planning. Shows worst-year drawdowns, recovery probability, and a histogram of outcomes.
If you've already got a 60/40 or 80/20 plan and want to know what happens in the next 1929-1932 or 2000-2002 scenario, this is the tool.
3. Roth Conversion Calculator 2026
Roth conversion math is where most calculators wave hands. This one actually models the multi-year tradeoff: pay tax now at your current bracket vs pay tax later at your expected retirement bracket, with federal + state brackets, ACA premium-cliff penalty, and IRMAA Medicare-surcharge dollar damage all surfaced. The PRO tier adds projection through your withdrawal horizon and break-even analysis.
The bracket math uses 2026 OBBBA brackets (not pre-TCJA values) and applies the correct senior bonus for 65+. The IRMAA dollar-damage estimator pulls from current CMS schedules.
4. RMD Calculator 2026
Once you hit age 73 (SECURE 2.0), required minimum distributions kick in. This one handles both the Uniform Lifetime Table (the default) and the Joint Life Table (when your spouse is 10+ years younger). Also calculates the 10-year projection and surfaces the April 1 first-RMD deadline.
Where most RMD calculators stop at the "divide by the IRS factor" step, this one estimates the tax impact at your filing status and surfaces inherited-IRA rules. PRO adds Roth conversion impact modeling.
5. FIRE Calculator
Coast FIRE, Barista FIRE, Lean FIRE — the standard FIRE shapes are all here, with real return inputs (nominal + inflation, not a fictional flat 7%). Tells you the FIRE number (annual expenses ÷ withdrawal rate), years to FIRE based on current savings rate, and what the math looks like under variant strategies.
PRO adds the geographic arbitrage comparison and the safe-withdrawal-rate sensitivity analysis. The free tier is enough for the baseline question of "am I on track?"
How they fit together
The five tools are deliberately scoped — each does one thing well rather than trying to be a one-tool-fits-all planner. Most users won't need all five; pick the ones that match where you are in the retirement-planning workflow:
- Plan-building from scratch: install #1 (Monte Carlo Retirement Calculator). Free, no PRO tier — the full feature set is on the free version.
- Stress-testing an existing plan: install #2 (MC Portfolio Stress Tester).
- Inside the 5-15 year ACA / IRMAA-sensitive window before Medicare: install #3 (Roth Conversion Calculator).
- Age 65+ and planning RMDs: install #4 (RMD Calculator).
- 30-50 and deciding if FIRE is viable: install #5 (FIRE Calculator).
For full-spectrum planning that goes beyond what an extension popup can host — 10,000-path Monte Carlo, tax-aware withdrawal sequencing across all 51 states, IRMAA + ACA cliff interactions, scenario optimizer, glide-path allocation — the web app at quantcalc.app covers the workflows the extensions deliberately don't. The extensions are scoped tools, not full planners; the web app is the complement.
One-click install: the Monte Carlo Retirement Calculator is the best starting point — full plan workflow, free forever, no signup. The other four are linked above and complement it cleanly.