Free Roth conversion optimizer with full cash-flow modeling. Enter your IRA, Roth, and brokerage balances, your living expenses, and your income — an optimization model finds the conversion and withdrawal plan that maximizes your after-tax wealth, paying the tax from the right account. Built with Python and PuLP.

I've spent 20+ years as an Operations Research analyst — built optimization models in Excel for supply chain and scheduling work, using SolverStudio/PuLP under the hood. When I started planning my own Roth conversions for FIRE, I built myself a proper optimizer instead of using a single-year "should I convert" calculator. Most Roth calculators I found just compare one year's tax bill. Mine treats it as what it actually is — a multi-year optimization problem — and solves for the conversion schedule that minimizes total lifetime tax, not just this year's number. It accounts for tax brackets, IRMAA thresholds, and how conversions today change your RMDs and taxes years down the road. It's completely free, no signup. I built it by porting one of my old Excel models into a small Python web app — happy to answer anything about the tax logic or the build itself.

Does the optimizer factor in future tax bracket changes, or is it assuming today's brackets stay flat for the whole planning horizon?

Plugged in my numbers and it actually showed me converting way more than I expected this year, which makes the tax bracket trade-off click in a way spreadsheets never did. Wish the UI had a quick way to compare two scenarios side by side, but for a free tool this is impressively thorough.

Love that it picks which account pays the conversion tax instead of assuming one bucket. That detail alone separates this from the basic conversion worksheets cluttering the space.

Does the optimizer factor in future tax bracket changes, or is it assuming today's brackets stay flat for the whole planning horizon?

Love that it picks which account pays the conversion tax instead of assuming one bucket. That detail alone separates this from the basic conversion worksheets cluttering the space.

Roth Conversion Calculator

Free Roth conversion calculator that minimizes lifetime tax

Free Roth conversion calculator that minimizes lifetime tax