Roth Conversion Limit Calculator
The first step in Roth conversion planning is deciding how much of your pretax account you actually intend to convert. Some dollars are better left where they are — either because they'll be tax-deductible when used for long-term care, or because they'll flow to charity completely free of income tax via QCD. What remains is your Roth Conversion Limit — the maximum you can convert without leaving behind dollars better sheltered in a pretax account.
Who is this plan for?
Pretax account growth assumption
Long-term care — retained in pretax account
↗ Look up today's LTC cost at CareScout
These dollars are deliberately retained in the pretax account. Qualified long-term care expenses paid from a pretax account are tax-deductible — converting them to Roth first means paying tax on dollars that would otherwise be sheltered.
Your LTC retention
Leave blank or enter $0 to exclude LTC from the calculation.
QCD — retained in pretax account
These dollars are deliberately retained in the pretax account. QCDs are completely excluded from AGI — they never appear as taxable income. Converting them to Roth first provides zero additional tax benefit.
QCDs are permitted once you reach age 70½. This is calculated automatically from your date of birth.
What to Keep in Pretax
How is the RMD adjustment calculated?

The starting point is a standard present value calculation — all future LTC and QCD costs are discounted back to today using the assumed growth rate. That gives the amount that, if left to grow untouched, would exactly cover every future obligation.

The problem is the retained pool isn't left untouched. The IRS requires minimum distributions (RMDs) from pretax accounts every year starting at age 72, 73, or 75 depending on birth year. Those withdrawals drain the account faster than growth can replenish it, so the simple present value figure isn't enough.

To find the true starting amount, the calculator uses a binary search:

  1. Start with the present value as a lower bound
  2. Simulate the retained pool year by year — apply growth, calculate the RMD using the IRS Uniform Lifetime Table (Pub. 590-B, 2022), let QCDs satisfy the RMD first, then deduct any remaining RMD and LTC costs
  3. Check whether the balance is sufficient before each LTC or QCD withdrawal is taken
  4. If there's a shortfall in any year, increase the starting amount and simulate again
  5. Repeat until the minimum starting balance is found where the pool never runs short

The RMD adjustment is the difference between that minimum starting balance and the original present value — the extra amount needed today because RMDs will be pulling money out between now and when LTC and QCDs are needed.

QCDs play a double role here — they are a planned outflow from the retained pool, but they also satisfy RMD obligations dollar-for-dollar. This means in years where QCDs are taken, the gross RMD is first reduced by the QCD amount, and only the remaining excess RMD is an additional drain on the retained pool. You can see this in the table above: years with QCDs will show a lower Net RMD than years without.