5 Best FIRE Calculators for Early-Retirement Planning
5 min read • This article was created using publicly available data at the time of publication. The list includes editorial opinions, is not investment advice, and there are no paid placements.
At their core, FIRE calculators distill complex retirement-planning concepts—savings rate, withdrawal rules, market variability—into actionable projections. Our review identified five free, web-based tools dedicated to early-retirement (FIRE) planning, each providing clear author or contact information for support, from straightforward 4 %-rule estimators to full Monte Carlo simulators.
Early-retirement planning hinges on understanding how savings, spending, and market returns interact over decades. Specialized FIRE calculators help track your “FIRE number” (target nest egg) and projected retirement age using rules like the 4 % withdrawal rate or historical-simulation methods. From basic rule-of-25 estimators to advanced Monte Carlo engines, these free web tools make complex modeling accessible without paid subscriptions.
How We Selected These FIRE Calculators
To compile this list, each entry had to:
- Be a free, fully web-based calculator
- Focus explicitly on FIRE (Financial Independence, Retire Early) projections
- Display clear contact or author information for user support
All five tools were active and updated as of mid-2025.
1. cFIREsim 3.0
- Cost: Free web tool
- Focus: Monte Carlo–based FIRE simulation using historical data back to 1871
- Access: Interactive web interface with customizable inputs tabs and simulation outputs
- Contact: “Email me” link prominently in the site navigation
- Notable Details: Offers dozens of simulation permutations, safe withdrawal rate analysis, inflation-adjusted returns, and year-by-year growth projections (data last updated Nov. 1, 2024)
2. MarketBeat FIRE Calculator
- Cost: Free
- Focus: Estimates years to FIRE based on current age, income, savings rate, and investment growth
- Access: Web-based form with interactive charts and sliders
- Contact: Author credit “Written by Jeffrey Neal Johnson | Reviewed by Don Miller” (June 10, 2024)
- Notable Details: Includes FAQ section, scenario comparisons at different savings rates, and print-friendly results
3. Money Under 30 FIRE Calculator
- Cost: Free
- Focus: Calculates your FIRE number and projected retirement age using expense, savings, and investment inputs
- Access: Web page form with adjustable fields for savings rate and return assumptions
- Contact: Site About page stating “feel free to contact me” by author David
- Notable Details: Slider for savings-rate adjustment, separate fields for cash versus investment accounts, and clear guidance on using the 4 % rule
4. MagnifyMoney FIRE Calculator
- Cost: Free
- Focus: Calculates FIRE goal and age with detailed input on income, expenses, savings contributions, and return assumptions
- Access: Web interface under “FINANCE TOOLS” with real-time result display
- Contact: “Contact” link in footer leading to LendingTree-hosted contact page
- Notable Details: Written methodology by Christina Majaski, integration with LendingTree advisory links, and a clear “How our FIRE calculator works” section
5. The FIRE Calculator
- Cost: Free
- Focus: Suite of calculators covering Lean, Coast, Barista, Fat, and standard FIRE scenarios
- Access: Web-based toolset with distinct calculators selectable from the main menu
- Contact: “About Us” and “Blog” links for more information and inquiries
- Notable Details: In-depth educational content, multiple strategy explanations, and customizable asset-allocation inputs
In Summary
These five calculators provide a range of approaches—from simple 4 %-rule estimators to full Monte Carlo simulators—while remaining cost-free, focused on FIRE principles, and backed by visible contact or author support.
Disclosures
- Data verified as of June 30, 2025
- This article is not financial advice
- FIRE calculator features and availability may change; always verify directly with each provider
