Don't let taxes eat away your goals

Most tools ignore taxes or oversimplify them—leaving you with a misleading plan. MOF gets it right, so you stay on track.

Accelerate your journey

Taxes are complex

When planning for FIRE, taxes quietly become one of the biggest drags on your progress—during both the accumulation phase (as you save) and the decumulation phase (as you withdraw). And yet, most calculators just... skip it. They either:

  • Assume your inputs are post-tax (leaving you to figure out how much you can save), or
  • Ignore how different accounts (401(k), IRA, Roth, 529, RSUs, brokerage) are taxed differently.

But here's the truth:

  • Saving to pre-tax accounts like 401(k)s reduces your tax burden, which impacts how much you can actually save
  • Tax brackets inflate over time, and vary by state, income, and filing status
  • Contribution limits, deduction rules, and account benefits aren't just confusing—they're interconnected
  • RSUs are taxed when they vest—and again if sold at a gain

Trying to build this into a spreadsheet? It's a nightmare of circular dependencies. One decision—like maxing your 401(k)—affects your taxable income, which affects your taxes, which affects your ability to contribute.

That's where most people give up—or get it wrong.

Tax Complexity in FIRE Planning

Why it matters: Most tools ask "How much are you saving?".
We ask, "How much can you save after taxes and obligations?"—and then show you how.

MOF does the heavy lifting for taxes

MOF Tax Optimization InterfaceMOF Scenario Planning PathMOF Scenario Planning FatFIRE

Most tools treat taxes as a footnote. MOF builds them into the core of your financial plan—dynamically, accurately, and automatically. Here's what sets our tax engine apart:

Smart tax modeling during accumulation

MOF doesn't ask for your post-tax savings. It simulates your actual income, expenses, and tax obligations, so it can:

  • Calculate your true take-home income after federal, state, FICA, and Medicare taxes
  • Determine exactly how much you can contribute to tax-advantaged accounts (like 401(k), IRA, HSA, 529) and then adjust your take-home pay
  • Model tax constraints like account contribution limits, state-specific deductions, and phase-outs
  • Prioritize your savings into the most tax-efficient accounts first (e.g., maxing employer match, Traditional, Roth)
  • Account for RSU vesting as taxable income and estimate capital gains if sold

Taxes influence your whole plan—we capture that

Unlike traditional calculators, MOF understands that taxes impact every layer of your plan:

  • Your savings rate changes based on how your income is taxed
  • Your expense estimates need to include after-tax cash flow
  • Your FIRE date is affected by whether you save in pre-tax or after-tax accounts
  • RSUs may push you into a higher bracket—MOF factors this in
  • Even your college contributions and property taxes vary by state—we adjust for that

It's not just math—it's a dynamic system with feedback loops. We model those loops for you.

Coming Soon: Even smarter tax optimization in retirement

We're already building these features into our roadmap:

  • Downsizing at FIRE (e.g., moving states or homes)
  • Withdrawal sequencing across account types to minimize taxes in retirement

MoneyOnFIRE makes tax planning part of your FIRE journey—not a footnote

Understand where your dollars go. Minimize what you owe. Stay on track to FIRE.

Start planning with tax smarts