WalletBurst FIRE Calculator

WalletBurst's FIRE Calculator is a free, browser-based tool for visualizing your net worth growth trajectory toward Financial Independence. It runs on web browsers with no signup or bank connection required, built by a creator who also publishes personal finance articles and tools on the WalletBurst site. The site also sells a separate product: a $20 "Wealth Planning Toolkit" for Google Sheets, which includes a 10-year net worth tracker with customizable dashboard, asset rebalancing calculator, advanced FIRE calculator with multiple scenarios, and Coast FIRE calculator. That Google Sheets product is a distinct purchase and not required to use the free web calculator, though it offers more depth for users comfortable working in spreadsheets.

Money entry is entirely manual, entered directly into the calculator interface. The calculator asks you to enter your current age, current annual take-home pay (your post-tax income, which the site specifies includes any contributions you make to retirement accounts like a 401k or HSA), current annual spending, and current net worth. Current net worth should include stocks, bonds, cash, and retirement accounts, but explicitly not real estate equity unless you plan to sell it in retirement and include those proceeds. The site notes that spending in retirement often drops below current spending because you will be covered by Medicare, and you may have already paid off your primary residence, eliminating mortgage payments. The site does not state the age at which Medicare coverage begins. You also specify your expected annual income growth rate, and the calculator compounds your salary growth separately from your investment growth. The calculator then projects your net worth year by year based on your inputs, displaying results in a visual graph. There is no option to connect a bank or import transactions; all figures must be entered manually, making it suitable for those who prefer to maintain their own assumptions rather than sync live spending data.

The calculator's core workflow centers on live visualization. You set your investment rate of return (it defaults to 7 percent, described as a relatively conservative assumption compared to the S&P 500's historical average of 10 percent from 1926 to 2018) and your inflation rate (defaulting to 3 percent, the historical US average). The Safe Withdrawal Rate (SWR) slider is set to 4 percent by default, which the site attributes to the Trinity Study's finding that a 4 percent annual withdrawal rate had a 100 percent success rate over a 30-year retirement horizon when applied to a 50 percent stock, 50 percent bond allocation. The calculator derives your FIRE number using the formula: FIRE number equals annual spending divided by your Safe Withdrawal Rate. The methodology uses the compound interest formula A equals P times (1 plus n) to the power of t, where A is the final amount, P is the principal, n is the annual growth rate, and t is time in years. It recursively calculates your net worth year by year, starting with your current net worth, then adding the annual difference between your take-home pay and your spending (your savings), accounting for investment growth minus inflation, and including any employer 401k match your job offers. Income grows each year by a salary increase percentage you specify, typically 2 to 4 percent. The graph updates live as you adjust any slider (age, income, spending, return rate, or inflation), so you can immediately see how each assumption change affects the graph trajectory and your projected FIRE age. This immediate visual feedback is the tool's strength for scenario exploration, changing one number shows the full cascade instantly.

The calculator is completely free to use with no pricing or paid tiers for the web tool itself. The separate $20 Google Sheets Wealth Planning Toolkit is optional and mentioned in a banner on the page, but is not required to use the free calculator. All calculations and results are available in the browser without any purchase or upgrade. The tool performs all calculations client-side in your browser, so no personal financial data is sent to any server. The site also highlights related free tools: Coast FIRE Calculator (which calculates how much you need invested to reach FIRE by stopping contributions early and letting investments compound), Barista FIRE Calculator (modeling lower-income part-time work in retirement to stretch savings), Savings Rate Calculator (showing what percentage of gross income you save annually), Hybrid vs Gas Savings Calculator (comparing vehicle ownership costs), Fat FIRE Calculator (for higher spending retirement goals), Electric Car Savings Calculator, Portfolio Rebalancing Calculator, and Compound Interest Calculator. The site includes a newsletter signup for followers interested in updates and publishes original content on FIRE topics, including recent articles about living on $39,000 per year and year-in-review personal finance summaries.

The WalletBurst FIRE Calculator suits anyone starting their FIRE planning who wants a quick visual answer to the question "At what age can I retire given my current assumptions?" It works best for people in the United States and those with simple financial lives (primarily salary income, one assumed investment return rate, no complex income or expense events). The real-time graph update makes it ideal for scenario testing: adjusting the savings, return-rate, spending, or working-longer sliders and watching the projected FIRE age update immediately, with no need to re-enter your whole plan. The visual nature of the tool helps early planners develop an intuition for how changes in savings rate, investment returns, and retirement spending affect their FIRE date. Because the tool defaults to reasonable middle-ground assumptions (7 percent returns, 3 percent inflation, 4 percent SWR), new FIRE planners can immediately see a baseline without having to research what assumptions to use.

It does not suit those needing to model complex life events (inheritances, major unexpected expenses, pension income that changes over time), detailed tax planning across different account types, or Monte Carlo simulations that stress-test against thousands of random market futures. Those advanced features appear in the paid Google Sheets toolkit and in other calculators linked from the site. The tool is educational and designed for quick visualization, and the site includes no endorsement of any specific investment product, broker, or investment approach. The creator positions the tool as a starting point for FIRE exploration and recommends the featured books (The Simple Path to Wealth, The Psychology of Money, and others in the FIRE canon) as next steps for deeper learning.