Roth Conversion & Drawdown Optimizer
A free tool that plans your whole retirement cash flow: it funds your living expenses, pays the tax on your income and conversions from the right account, and finds the conversion schedule that leaves you the most after-tax wealth.
Result
Year-by-year plan
| Age | IRA | Roth | Taxable | RMD | Convert | IRA draw | Roth draw | Taxable sold | Spending | Taxable inc | Top rate | Tax |
|---|
Not tax or investment advice. This tool models your living expenses and draws them — plus the tax on your income and conversions — from your accounts in order (taxable → traditional → Roth by default), and picks the conversion schedule that maximizes after-tax wealth at the end. It still simplifies real tax law: a single real return; Social Security taxed at a flat fraction; long-term gains taxed at a flat rate (no 0%-bracket harvesting yet); and state income tax modeled only as one flat rate you enter — it ignores each state's brackets, retirement-income exclusions, and Social Security treatment, so treat it as a rough estimate. It also does not model IRMAA, NIIT, dividend tax-drag, or ACA-subsidy effects. Pre-59½ withdrawals from the IRA/Roth incur the 10% penalty; conversions never do. Results depend entirely on your assumptions. Confirm any plan with a qualified tax professional before acting. Built by Kind-of-Lost.
How this works
A Roth conversion means paying income tax now on money in a traditional IRA or 401(k) so it can grow tax-free in a Roth account for the rest of your life. But conversions don't happen in a vacuum — they compete with your living expenses, your capital gains, and which account pays the tax bill, for space in your yearly income.
This calculator treats the whole picture as one optimization problem instead of solving conversions in isolation. It's a linear program — built with Python, PuLP, and the CBC solver — that plans your full retirement cash flow at once: it funds your living expenses every year, decides which account pays for that spending and for the tax on your conversions and withdrawals, and finds the conversion schedule that leaves you with the most money after tax at the end of the horizon, not just the lowest conversion-tax bill.
It also handles pieces most free calculators skip: capital gains on your brokerage account, split into long-term and short-term and taxed at their own rates; an optional withdrawal order the optimizer can choose instead of a fixed taxable-then-traditional- then-Roth sequence; and a "spend it down" mode that finds the most you can spend every year while draining every account to roughly zero by the end.
It's built for people within a few years of retirement or already retired, with meaningful balances across traditional, Roth, and taxable accounts, who want an answer built on real optimization math rather than a spreadsheet rule of thumb. It's not a substitute for a CPA or financial planner — state tax is modeled as one flat rate, and IRMAA, NIIT, and ACA subsidies aren't included — but it's a real, free starting point. For the reasoning behind the model, see when a Roth conversion makes sense and the linear-program math behind this calculator.
Frequently asked questions
How is this different from a simple Roth conversion calculator?
Most Roth conversion calculators only decide the yearly conversion amount and assume your other accounts just grow untouched. This tool plans your whole retirement cash flow at once: living expenses, withdrawal order, and capital gains on your brokerage account. It finds the conversion schedule that produces the most money in your pocket after tax, not just the lowest conversion-tax bill in isolation.
What does "maximize after-tax wealth" mean, exactly?
It compares every plan by what's left across your traditional IRA, Roth IRA, and taxable brokerage at the end of your horizon, after subtracting the tax you'd still owe on the traditional balance and the embedded capital gain in the brokerage account. That number is your after-tax wealth, and it's what the optimizer maximizes.
What is the "spend it down" mode?
Instead of you specifying a living-expense number, this mode asks the solver for the highest constant amount you can spend every year, in today's dollars, while still funding taxes and RMDs, such that all three accounts land at roughly zero by your planning end age. It's a die-with-zero style plan rather than a wealth-maximizing one.
Does it really model my state taxes?
It applies one flat rate you enter to your taxable income and realized gains, not your actual state's brackets, retirement-income exclusions, or Social Security treatment. It's meant as a rough estimate so no-income-tax states like Florida or Texas aren't unfairly penalized in the comparison, not as a substitute for real state tax software.
What isn't included in this calculator?
This version doesn't model IRMAA Medicare premium surcharges, the Net Investment Income Tax, ACA subsidy phase-outs, or 0%-bracket capital-gains harvesting. It uses a single real rate of return for every account and a flat long-term capital-gains rate. Treat the output as a starting point to bring to a CPA or financial planner, not a final plan.